Possible Columnaris On Pleco

I noticed last night that my largest pleco has a large whiteish almost clear spot on his head. Until yesterday I did not notice any afflictions or odd behavior. He still seems to be acting normal this morning, swimming about as much as he normally does and the food I dropped in before going to bed is gone. However I fear this may be a columnaris infection but wanted to get the opinions of some more experienced before I started any kind of treatment. I've kept fish years ago but just recently got back into it about three months ago, the Pleco in question is housed in a 120gallon tank I got second hand a little over a month ago. It is lightly planted and because all rocks (new gravel) and filter was used in an established aquarium it seems to have cycled pretty quickly. I tested for ammonia yesterday and it was <0.25ppm and while I don't have a nitrate test kit at home I had the water tested at the LFS two weeks ago and they said it was 0. I will take another sample later today. Since this appeared so suddenly I am wondering if it is just an injury and not something to get so worried about. I know he lays under lava rocks, sometimes under ones he really can not fit under so perhaps he scraped himself. If it is just an injury what can I do to aid in healing? The pleco is almost 8 inches long, and if I do need to treat him the only hospital tank I have is a small 10 gallon, is that going to be acceptable since its only temporary or should I get at least a 20?


Tank size: 120 Gallon
pH: N/A
ammonia: <0.25
nitrite: 0 (As of two weeks ago)
nitrate: 0 (As of two weeks ago)
kH: N/A
gH: N/A
tank temp: 78F

Fish Symptoms: Whiteish/pinkish/clear lesion on head, seems to still be eating and swimming as normal, just noticed it yesterday when I was feeding fish before bed. No other fish affected as far as I can tell.

Volume and Frequency of water changes: 10% weekly

Chemical Additives or Media in your tank: Added API Stress Zyme and Seachem Clarity water clarifier one week before adding fish, added Jungle Start Zyme one day before adding fish, washed filter media often during the first week as the well water is nasty and the clarifier gunked the filter bad. Nothing added since I placed fish in tank.

Tank inhabitants: Angels, Mollies, Clown Loaches, Plecos, Mystery Snails, Various live plants, Natural and artificial rocks

Recent additions to your tank (living or decoration): Added 5 small angels and 3 small clown loaches and about 10 aquarium plant bulbs 48h ago (36h before I noticed symptoms)

Exposure to chemicals: See above

Kerf said:

I noticed last night that my largest pleco has a large whiteish almost clear spot on his head. Until yesterday I did not notice any afflictions or odd behavior. He still seems to be acting normal this morning, swimming about as much as he normally does and the food I dropped in before going to bed is gone. However I fear this may be a columnaris infection but wanted to get the opinions of some more experienced before I started any kind of treatment. I've kept fish years ago but just recently got back into it about three months ago, the Pleco in question is housed in a 120gallon tank I got second hand a little over a month ago. It is lightly planted and because all rocks (new gravel) and filter was used in an established aquarium it seems to have cycled pretty quickly. I tested for ammonia yesterday and it was <0.25ppm and while I don't have a nitrate test kit at home I had the water tested at the LFS two weeks ago and they said it was 0. I will take another sample later today. Since this appeared so suddenly I am wondering if it is just an injury and not something to get so worried about. I know he lays under lava rocks, sometimes under ones he really can not fit under so perhaps he scraped himself. If it is just an injury what can I do to aid in healing? The pleco is almost 8 inches long, and if I do need to treat him the only hospital tank I have is a small 10 gallon, is that going to be acceptable since its only temporary or should I get at least a 20?


Tank size: 120 Gallon
pH: N/A
ammonia: <0.25
nitrite: 0 (As of two weeks ago)
nitrate: 0 (As of two weeks ago)
kH: N/A
gH: N/A
tank temp: 78F

Fish Symptoms: Whiteish/pinkish/clear lesion on head, seems to still be eating and swimming as normal, just noticed it yesterday when I was feeding fish before bed. No other fish affected as far as I can tell.

Volume and Frequency of water changes: 10% weekly

Chemical Additives or Media in your tank: Added API Stress Zyme and Seachem Clarity water clarifier one week before adding fish, added Jungle Start Zyme one day before adding fish, washed filter media often during the first week as the well water is nasty and the clarifier gunked the filter bad. Nothing added since I placed fish in tank.

Tank inhabitants: Angels, Mollies, Clown Loaches, Plecos, Mystery Snails, Various live plants, Natural and artificial rocks

Recent additions to your tank (living or decoration): Added 5 small angels and 3 small clown loaches and about 10 aquarium plant bulbs 48h ago (36h before I noticed symptoms)

Exposure to chemicals: See above

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That looks like a wound, possibly a burn? I'd change a bunch of water and watch it real close today to see if it's really progressing. If it grew from a small infection to that in 12 hours, then it should be visibly worse than the photo shows. If it doesn't progress today, then it is probably a wound of some kind. I wouldn't be surprised if he parked himself between the heater and the glass and got burned.

I'm a water change freak, I'm a believer in changing at least 25% per week.

Another thing, two week old nitrIte readings aren't current enough. The ammonia spike can come and go in a few days, but the nitrIte spike can go on for weeks while the bacteria slowly builds up. To make matters worse, if the nitrItes get too high, the bacteria will stop multiplying as too much food is poisonous to them too thus stalling the cycle.

Well I just changed 10% water again, that makes 20% in three days, I'll have to find a better way to do it as our water is so nasty I have to treat it for around 12-24h with the clarifying chemical, what I've been doing is filling up jugs with a friends tap water then waiting 3-4 days for the chlorine to dissipate. I could use our softened water but the salt content of that worries me. I did however find a floating snail today when I was changing the water, not sure if that points to out of range water parameters or if its just a coincidence.

As I am writing this the Pleco in question is currently stuck to the glass as he is most days, why would be sit so close to the heater for a long enough time to get burnt? I'd think he would move away when he started to feel pain, is this partly my fault? Should I try to give him better places to hide? I have noticed that he swims up and breaks the surface of the water a few times a day, does this mean the water is not oxygenated enough, or is this just something he likes doing? I don't notice many of the other fish doing it much if at all, but he is the largest fish in the tank right now. I have a total of six live plants, two power heads and a power filter which breaks the surface of the water. I also have two air stones four inches long running on a Top Fin AIR-3000, this this setup sufficient? Like I said I have kept fish in the past, but never such a large tank or one with live plants and powerheads. I took a water sample before the 10% change today, and I am going now to have it analyzed.

Kerf said:

Well I just changed 10% water again, that makes 20% in three days, I'll have to find a better way to do it as our water is so nasty I have to treat it for around 12-24h with the clarifying chemical, what I've been doing is filling up jugs with a friends tap water then waiting 3-4 days for the chlorine to dissipate. I could use our softened water but the salt content of that worries me. I did however find a floating snail today when I was changing the water, not sure if that points to out of range water parameters or if its just a coincidence.

As I am writing this the Pleco in question is currently stuck to the glass as he is most days, why would be sit so close to the heater for a long enough time to get burnt? I'd think he would move away when he started to feel pain, is this partly my fault? Should I try to give him better places to hide? I have noticed that he swims up and breaks the surface of the water a few times a day, does this mean the water is not oxygenated enough, or is this just something he likes doing? I don't notice many of the other fish doing it much if at all, but he is the largest fish in the tank right now. I have a total of six live plants, two power heads and a power filter which breaks the surface of the water. I also have two air stones four inches long running on a Top Fin AIR-3000, this this setup sufficient? Like I said I have kept fish in the past, but never such a large tank or one with live plants and powerheads. I took a water sample before the 10% change today, and I am going now to have it analyzed.

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Hmmmm, the days are gone of letting water sit to remove chlorine. You absolutely must use a real dechlorinator as the water utilities put chloramines in and they don't break down in 24 hours, they take weeks. Prime is a popular water treatment.

I don't know about plecs, but at least some fish sleep. He could have parked next to it when it was off, but slightly warm and zonked out (however a plec does it) and then the heater came on and scorched him before he "woke up". Who really knows if a fish would feel a burning item as anything more than something warm. Unlike us, they wouldn't likely encounter extremely warm temps ever so I have to question if they'd "evolve" the ability to sense it as anything more than "too warm". Peoples fish seem to get burned all the time, and the only way that could really happen is for the fish to stay against the heater for a fair amount of time. When surrounded by water, the glass just doesn't get all that hot, but when you put some flesh against it, the temp will climb right on up.

afremont said:

Hmmmm, the days are gone of letting water sit to remove chlorine. You absolutely must use a real dechlorinator as the water utilities put chloramines in and they don't break down in 24 hours, they take weeks. Prime is a popular water treatment.

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Would chloramines show up on a chlorine test strip? I just got back from the fish store and they told me my chlorine count was zero, also how easy is it to remove chloramines via filtration? I use filtered tap when I fill my jugs, the filter is a 2 micron nominal 5 micron absolute solid carbon block.

Anyway about the test, it was anything but good. Ammonia and chlorine were zero, but the good news stops there. Ph was ~7, nitrate NO3 was ~180 while nitrite NO2 was off the charts at >10. The only thing they recommended at the fish store was a water change for the short term, and long term just let it cycle, I could add a culture to speed up the process if I wanted.

What do you recommend for bringing down the NO2/3 both long and short term? How much would additional live plants help? I know high levels stress the fish and can even be toxic, but should I bring them down slowly by doing 10% changes daily for a week, or should I just do a 50% change to cut levels quick? Will extremely hard water have any effect negative or positive on the fish? I know the water should be a little hard for the snails. The tank is still relatively new so this is to be expected, I just want to be reassured I am on the right track and if not make the needed changes before I lose all my fish.

As for my Pleco you all have me feeling pretty comfortable that it's just an injury and not a columnaris outbreak, but I will still watch him and the other fish very closely over the next week or two.

Kerf said:

afremont said:

Hmmmm, the days are gone of letting water sit to remove chlorine. You absolutely must use a real dechlorinator as the water utilities put chloramines in and they don't break down in 24 hours, they take weeks. Prime is a popular water treatment.

Click to expand...

Would chloramines show up on a chlorine test strip? I just got back from the fish store and they told me my chlorine count was zero, also how easy is it to remove chloramines via filtration? I use filtered tap when I fill my jugs, the filter is a 2 micron nominal 5 micron absolute solid carbon block.

Anyway about the test, it was anything but good. Ammonia and chlorine were zero, but the good news stops there. Ph was ~7, nitrate NO3 was ~180 while nitrite NO2 was off the charts at >10. The only thing they recommended at the fish store was a water change for the short term, and long term just let it cycle, I could add a culture to speed up the process if I wanted.

What do you recommend for bringing down the NO2/3 both long and short term? How much would additional live plants help? I know high levels stress the fish and can even be toxic, but should I bring them down slowly by doing 10% changes daily for a week, or should I just do a 50% change to cut levels quick? Will extremely hard water have any effect negative or positive on the fish? I know the water should be a little hard for the snails. The tank is still relatively new so this is to be expected, I just want to be reassured I am on the right track and if not make the needed changes before I lose all my fish.

As for my Pleco you all have me feeling pretty comfortable that it's just an injury and not a columnaris outbreak, but I will still watch him and the other fish very closely over the next week or two.

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I don't know if they would show up on the test or not. After using a plain dechlorinator (sodium thiosulphate), the remaining ammonia would show up. Modern dechlorinators like Prime not only release the chlorine, they break the chloromine bond and bind up the free ammonia for 24 to 48 hours. It also chelates heavy metals so it's probably a good idea to use it regardless of your water source.

Ouch that's definitely some bad water quality on the nitrItes and nitrAtes. If you can, the best thing now would be to put your fish in a temporary home and drain the whole tank and refill and treat the new water with Prime. I don't know what you are using for a filter in the tank, but allot of water clarifiers (floculants) can stop up the filter media over time. I can't imagine that your tap water is so bad that it would be worse than what is in the tank right now. The fish don't care how clear it is, just how toxic it is.

Look at your fishes gills, are they pinkish red or brownish, this is key. High nitrItes can cause serious issues with the oxygen transfer to the fish. They can convert hemoglobin in the blood to methemoglobin making it impossible for the fish to get oxygen even though there is plenty in the water. Methemoglobin turns the blood brown creating a condition known as Brown Blood Disease. The problem is not that the blood won't take on oxygen as it does just fine, it just can't release it to the cells so the fish slowly suffocates from lack of oxygen even though the gills are perfect. I know you didn't want to hear that, but it's fish knowledge that everyone needs to know. A miniscule amount of salt in the water can prevent further damage since chloride ions beat out the nitrItes for getting thru the gills preventing the absorption of the nitrItes and consequently the conversion of the hemoglobin. This might not be the problem, but it sure seems like a good candidate given the water parameters and the behavior of the fish.

Hypothetically if it were me, this is what I'd do. I'd put all the fish in a bucket of good, salted water with an airstone and a heater. I'd put in 1 teaspoon (5mL) of methylene blue per TEN (10) gallons of water until I could put them back into the main tank. This would reverse the damage of the nitrItes very quickly by converting the methemoglobin back to fully functioning hemoglobin without waiting for nature to do it over weeks. It is completely safe for the fish. If they died, it wouldn't be because methylene blue killed them unless I massively overdosed it. Meanwhile, I'd drain and refill the tank with new water and treat it with Prime not worrying about extreme clarity as the filter will get allot of that on its own.

I'm not trying to be ugly, but you have to do something about your water quality, it is in all likelihood the root cause of the fish's health problems. EDIT3: strike this since the other fish don't seem to have any health problems, I still think the plec looks like it has a wound.

EDIT: I understand your concern about shocking the fish from sudden water quality changes, but in this case I think it's paramount that you reduce the nitrItes immediatly. I guess the first thing you can do is put some aquarium salt in the tank right now to stop further damage from the nitrItes.

EDIT 2: After reading thru the thread again, none of the fish seem to show any signs of high nitrItes such as panting etc. Maybe the test results are a little off and just doing large water changes for now would be good enough. I'm surprised that the fish don't show any signs of problems from the nitrItes at that level.

Thank you all for your help and advice, here is an update on my status. I did a 40% water change last night, I am going to do another 30-40% water change this afternoon, however the pleco situation has continued to worsen. The wound on the large pleco I posted yesterday looks about the same, however he has some discoloration on his nose now too (photo 1), and the second largest pleco now has missing scales on his side as well (photo 2). Do plecos get territorial and fight? The plecos have been together since the were introduced to the tank a few years ago and I never had a problem until now, could the stress of the NO2 and NO3 be causing them to fight? None of the other fish have ever shown any aggression, and the only one large enough to do so is the angel, which has also been living in harmony with the plecos since its introduction a few years back.

Kerf said:

Thank you all for your help and advice, here is an update on my status. I did a 40% water change last night, I am going to do another 30-40% water change this afternoon, however the pleco situation has continued to worsen. The wound on the large pleco I posted yesterday looks about the same, however he has some discoloration on his nose now too (photo 1), and the second largest pleco now has missing scales on his side as well (photo 2). Do plecos get territorial and fight? The plecos have been together since the were introduced to the tank a few years ago and I never had a problem until now, could the stress of the NO2 and NO3 be causing them to fight? None of the other fish have ever shown any aggression, and the only one large enough to do so is the angel, which has also been living in harmony with the plecos since its introduction a few years back.

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Good deal on the water changes, what kind of dechlorinator did you use?

afremont said:

Good deal on the water changes, what kind of dechlorinator did you use?

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I used "Seachem Prime for Freshwater and Saltwater", but I only treated and added about 20 gallons of tap water, the rest (apx 30 gallons) I used our softened water since you told me adding salt to the aquarium helps reduce the effects of high nitrites.

Kerf said:

afremont said:

Good deal on the water changes, what kind of dechlorinator did you use?

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I used "Seachem Prime for Freshwater and Saltwater", but I only treated and added about 20 gallons of tap water, the rest (apx 30 gallons) I used our softened water since you told me adding salt to the aquarium helps reduce the effects of high nitrites.

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Can you actually taste salt in your softened water? If not, then it's not all that salty. One half teaspon of aquarium salt in a gallon of water tastes pretty salty. Keep an eye on pH since you are changing your water source, pH shock is bad too and some fish won't tolerate large sudden change. If there is a big discrepancy in the numbers between the two sources then be careful to acclimate the fish to the change gradually. You know your fish better than anyone, you can tell when something is bothering them.

I'm sorry I don't know anything about plecs, other than they can get really big. Since the wound on the first fish didn't grow to cover it's body and kill the fish by now, I think it's safe to assume that it is not columnaris and because it showed up so suddenly I'd tend to think it is a wound and not an infection caused ulcer.

afremont said:

Can you actually taste salt in your softened water? If not, then it's not all that salty. One half teaspon of aquarium salt in a gallon of water tastes pretty salty.

I'm sorry I don't know anything about plecs, other than they can get really big. Since the wound on the first fish didn't grow to cover it's body and kill the fish by now, I think it's safe to assume that it is not columnaris and because it showed up so suddenly I'd tend to think it is a wound and not an infection caused ulcer.

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The vast majority of my life I had treated city water from Lake Erie, I remember I had a friend as a kid who had well water, and I remember his softened water tasted just like the stuff I have at the house now, which tastes like flippin' sea water to me. Back then he always told me, and my wife tells me now, that they can not even taste the salt (while I'm secretly turning down the ppm until rust starts showing and I get busted). I taste it in everything even tea and coffee, so I just assumed, perhaps wrong, that it was quite salty. As for the PH we had the water analysed when we move in, and it was 7.2. The test I had done yesterday said the tank was ~7 so I figured it would not be an issue.

As for the Plecos I am fairly confident now that it is not columnaris, I just panicked yesterday because when I saw the wound that is the first thing that came to mind, and I know how fast that can wipe out a tank. Perhaps I should make a new post since the discussion turned towards water quality and away from columnaris, and also it does not seem to be an emergency since I may have caught it just in time as to not negatively affect the fish in any noticeable way. I think the Plecos just have an injury like others suggested. It does however concern me that a second Pleco has wounds now too, which leads me to believe something is picking on them. I will have to keep a close eye on their tank mates.

Kerf said:

afremont said:

Can you actually taste salt in your softened water? If not, then it's not all that salty. One half teaspon of aquarium salt in a gallon of water tastes pretty salty.

I'm sorry I don't know anything about plecs, other than they can get really big. Since the wound on the first fish didn't grow to cover it's body and kill the fish by now, I think it's safe to assume that it is not columnaris and because it showed up so suddenly I'd tend to think it is a wound and not an infection caused ulcer.

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The vast majority of my life I had treated city water from Lake Erie, I remember I had a friend as a kid who had well water, and I remember his softened water tasted just like the stuff I have at the house now, which tastes like flippin' sea water to me. Back then he always told me, and my wife tells me now, that they can not even taste the salt (while I'm secretly turning down the ppm until rust starts showing and I get busted). I taste it in everything even tea and coffee, so I just assumed, perhaps wrong, that it was quite salty. As for the PH we had the water analysed when we move in, and it was 7.2. The test I had done yesterday said the tank was ~7 so I figured it would not be an issue.

As for the Plecos I am fairly confident now that it is not columnaris, I just panicked yesterday because when I saw the wound that is the first thing that came to mind, and I know how fast that can wipe out a tank. Perhaps I should make a new post since the discussion turned towards water quality and away from columnaris, and also it does not seem to be an emergency since I may have caught it just in time as to not negatively affect the fish in any noticeable way. I think the Plecos just have an injury like others suggested. It does however concern me that a second Pleco has wounds now too, which leads me to believe something is picking on them. I will have to keep a close eye on their tank mates.

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My parents have soft water and I can't stand it when I'm up there. I don't really drink it, but I hadn't noticed any saltiness to it that stuck out. I can't handle taking a shower in it, it makes skin feel like it's all slimy to me. It also seems like the soap isn't coming off. Of course my skin seems to like it since it doesn't get all dry when I'm there, even in the winter.

As for the first pleco, I suppose it's possible, but I've never read about columnaris spreading fast then stopping without some kind of big intervention. I don't think your water changes would be the kind of intervention that would halt columnaris in its tracks.

Good luck with your fish, I'm looking forward to hearing how they turn out.

Well heres an update, I went away last weekend and when I returned my fish were much worse, it was clearly columnaris and covered nearly 40% of the largest Pleco's body. I immediately quarantined the two affected Plecos and started a treatment with both Maracyn and Maracyn Two. In less than two days the largest Pleco passed. I did the full five day treatment on the hospital tank, and also treated the main tank with 60% strength Pimafix for a week as a preventative. It has been three days since I ended treatment and I have not yet done a water change on the hospital tank, looking at the Pleco still in the tank the well defined white spots are gone, and the wound on his side is almost fully healed. He still looks like he has a bit of white but not in defined spots, sort of all over him but not intense more like just a dulling of his coloration. I am not sure if this is him changing his coloration because of his new surroundings or due to the medication he was/is exposed to, or if he still has a mild case of columnaris. Should I just change the water out in the hospital tank and watch him for another day or so, or should I start a second round of treatment after the water change?

The main tank is now back on track with the NO2, however I lost two corys during the spike, glad I noticed when I did otherwise I surly would have lost the entire tank. I have not noticed any odd behavior or any white spots of any kind on the other fish in the tank, so I'm think we are all clear. Everything I read says it's an opportunistic infection, and I am most sure the high NO2 levels stressed the fish lowering their immune system, then when the Plecos got injured it just set the stage for infection.

Thank you all very much for you help, without you the NO2 spike in my main tank would have claimed many more fish, any advice you can now give me on issuing the all clear and returning the Pleco to the community tank would be appreciated.

Kerf said:

Well heres an update, I went away last weekend and when I returned my fish were much worse, it was clearly columnaris and covered nearly 40% of the largest Pleco's body. I immediately quarantined the two affected Plecos and started a treatment with both Maracyn and Maracyn Two. In less than two days the largest Pleco passed. I did the full five day treatment on the hospital tank, and also treated the main tank with 60% strength Pimafix for a week as a preventative. It has been three days since I ended treatment and I have not yet done a water change on the hospital tank, looking at the Pleco still in the tank the well defined white spots are gone, and the wound on his side is almost fully healed. He still looks like he has a bit of white but not in defined spots, sort of all over him but not intense more like just a dulling of his coloration. I am not sure if this is him changing his coloration because of his new surroundings or due to the medication he was/is exposed to, or if he still has a mild case of columnaris. Should I just change the water out in the hospital tank and watch him for another day or so, or should I start a second round of treatment after the water change?

The main tank is now back on track with the NO2, however I lost two corys during the spike, glad I noticed when I did otherwise I surly would have lost the entire tank. I have not noticed any odd behavior or any white spots of any kind on the other fish in the tank, so I'm think we are all clear. Everything I read says it's an opportunistic infection, and I am most sure the high NO2 levels stressed the fish lowering their immune system, then when the Plecos got injured it just set the stage for infection.

Thank you all very much for you help, without you the NO2 spike in my main tank would have claimed many more fish, any advice you can now give me on issuing the all clear and returning the Pleco to the community tank would be appreciated.

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Sorry to hear about your fish. Glad to hear the other one is doing much better. I think you should do a water change on the hospital tank especially if you don't have any kind of biofilter on it. So, in the picture, it looked to me like the skin was kind of melted or indented in, that's why I thought it a wound. I take it that, in reality, the stuff was sort of piled up on the skin? Or did they really have wounds and then the fuzz set in? Didn't it appear to be a fungus type substance growing over the fish?

afremont said:

Sorry to hear about your fish. Glad to hear the other one is doing much better. I think you should do a water change on the hospital tank especially if you don't have any kind of biofilter on it. So, in the picture, it looked to me like the skin was kind of melted or indented in, that's why I thought it a wound. I take it that, in reality, the stuff was sort of piled up on the skin? Or did they really have wounds and then the fuzz set in? Didn't it appear to be a fungus type substance growing over the fish?

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I am pretty sure that the first picture I posted was just a wound, but I think the wound gave the infection a chance to take hold. Since my water quality was very poor with the large NO2 spike surly all my fish were stressed, and therefore had a reduced immune systems. When both Plecos got injured it set the stage for the infection. The rest of my fish including other Plecos that did not get injured, have thus far not contracted anything.

Anyway I did a large water change yesterday on the hospital tank, and I just went and looked at the Pleco still in isolation, hoping to move him back into the main tank today. It appears he is still infected and it is starting to spread again. He has a largish white sport on his belly about the size of a dime, and also smaller white spots sprinkled over the rest of his belly. It may also be on his tail a little bit. It does sort of resemble a fungus as it appears to be a white powder on the skin, however on close inspection it does not have the "hair" you would expect on a true fungus. I diagnosed it as columnaris due to similar appearance and also because I have read that many mistake it for a fungus but to check for the "hair" to be sure. I am now however starting to second guess my diagnosis, the Maracyn and Maracyn Two did fight it back quite efficiently, should I start a second round of treatment or should I try something else? Should I switch meds entirely or add something in addition to Maracyn and Maracyn Two?

I really hope I can save this guy, I already lost the ~10 inch Pleco, this guy is almost 8 inches and my next biggest is barely 3, in a 120g tank he looks like a minnow.

Attached is a picture of the Pleco in isolation, unfortunately the picture did not turn out very good due to glare.