Fin rot

[Reily]

Hi,
I’m wondering if anyone can help solve the problem I’m having. I did a 50% water change about two weeks ago in my freshwater tropical aquarium and everything was fine all the fish were good until about a week ago when I noticed all three of my plecos had fin rot on their top fins. One has since passed and the others seem to be kind of recovering. I’m thinking it might be the temperature of the water that I put in when I added water. Could the temperature shock do that to a fish? None of my other fish seem to be affected. The plecos don’t even seem affected besides the fact that their fins are rotted. Should I isolate the two with fin rot?

The tank is 75 gallons kept @ 76°. I have 4 angels, 9 gouramis and the two plecos. I’ve had the tank setup for 5 months now. The plecos are about 7 years old. The angels and gouramis are new about 4 weeks.

pH: 8.2
Amonia: .25ppm
Nitrate NO3: between 20 and 40ppm (probably 35ppm)
Nitrite NO2: 0ppm

Thanks.

 

[GaryE]

If you did a 50% water change 2 weeks ago, what water change have you done since. You have quite a bioload in there, and plecos are rough on water quality. A 50% water change once a week, as a regular routine would be my suggestion. See if the spots on the fins clear after about 3 weeks. then stay the course.

 

[TNG]

Hi,
I’m wondering if anyone can help solve the problem I’m having. I did a 50% water change about two weeks ago in my freshwater tropical aquarium and everything was fine all the fish were good until about a week ago when I noticed all three of my plecos had fin rot on their top fins. One has since passed and the others seem to be kind of recovering. I’m thinking it might be the temperature of the water that I put in when I added water. Could the temperature shock do that to a fish? None of my other fish seem to be affected. The plecos don’t even seem affected besides the fact that their fins are rotted. Should I isolate the two with fin rot?

The tank is 75 gallons kept @ 76°. I have 4 angels, 9 gouramis and the two plecos. I’ve had the tank setup for 5 months now. The plecos are about 7 years old. The angels and gouramis are new about 4 weeks.

pH: 8.2
Amonia: .25ppm
Nitrate NO3: between 20 and 40ppm (probably 35ppm)
Nitrite NO2: 0ppm

Thanks.

From your previous posts you seem to have intermittent problem with fin rot. Did you successfully treat it in the past?

The ammonia is 0.25ppm. While that alone is unlikely to be the cause of fin rot, it’s a concern as your tank is 5 months old so ammonia should be zero. This ammonia suggests other recent underlying problems that need to be looked into (the plecos are 7 years old so they are well looked after). Did you recently treat your tank and the medication kills off the beneficial bacteria? Have you changed the water change frequency.

The pH is 8.2. Do you have hard tap water or do you use crushed shell as your substrate? While you currently don’t have problem with the angelfish, they need water with lower pH, so that’s something to consider as well.

 

[Reily]

From your previous posts you seem to have intermittent problem with fin rot. Did you successfully treat it in the past?

The ammonia is 0.25ppm. While that alone is unlikely to be the cause of fin rot, it’s a concern as your tank is 5 months old so ammonia should be zero. This ammonia suggests other recent underlying problems that need to be looked into (the plecos are 7 years old so they are well looked after). Did you recently treat your tank and the medication kills off the beneficial bacteria? Have you changed the water change frequency.

The pH is 8.2. Do you have hard tap water or do you use crushed shell as your substrate? While you currently don’t have problem with the angelfish, they need water with lower pH, so that’s something to consider as well.

Water changes seemed to help in the past. I have soft water. I haven’t recently added any medicine to the water. How do I safely lower the ph in the tank and how do I keep it that way?

 

[TNG]

Water changes seemed to help in the past. I have soft water. I haven’t recently added any medicine to the water. How do I safely lower the ph in the tank and how do I keep it that way?

I’d keep up the water change.

Many people advocate large water change, 50 to 70%. For a 75 US Gal (approx 300 litres), 50 – 70% would mean 150 to 200L of water change. For someone who does manual water change, that would mean carrying 15 to 20 of 10 litre buckets, not something I’d look forward to.
Instead I do 20 – 25% water change but do it more often and get into a routine of doing it. Also, smaller water change mean low temperature variations.

If you have soft water, which I assume you mean low pH and GH, but water in the tank has high pH, then there must be something in the tank which raises the pH. This may be crushed shell substrate, coral or pieces of limestone. If you remove them, the pH should drop, but don’t remove them all at once as you want the pH to slowly drop. I’d keep the pH around 7.2 as you need to accommodate the plecos as well.
To test for pH of your substrate or decorations, leave tap water over night in a container then test for pH the following day. Then drop your decoration in the water and leave it overnight, and test for pH the next day.

Another thing is feeding. I like to give Angelfish and Gouramis flakes mixed with slow sinking pellets and only enough for them to eat in 30 seconds or so. I don’t keep Plecos so can’t comment on them.

 

[Reily]

I’d keep up the water change.

Many people advocate large water change, 50 to 70%. For a 75 US Gal (approx 300 litres), 50 – 70% would mean 150 to 200L of water change. For someone who does manual water change, that would mean carrying 15 to 20 of 10 litre buckets, not something I’d look forward to.
Instead I do 20 – 25% water change but do it more often and get into a routine of doing it. Also, smaller water change mean low temperature variations.

If you have soft water, which I assume you mean low pH and GH, but water in the tank has high pH, then there must be something in the tank which raises the pH. This may be crushed shell substrate, coral or pieces of limestone. If you remove them, the pH should drop, but don’t remove them all at once as you want the pH to slowly drop. I’d keep the pH around 7.2 as you need to accommodate the plecos as well.
To test for pH of your substrate or decorations, leave tap water over night in a container then test for pH the following day. Then drop your decoration in the water and leave it overnight, and test for pH the next day.

Another thing is feeding. I like to give Angelfish and Gouramis flakes mixed with slow sinking pellets and only enough for them to eat in 30 seconds or so. I don’t keep Plecos so can’t comment on them.

Hi thanks for the response, I’ve lessened feeding and I don’t have crushed shell substrate it’s just colored rocks from the pet store very basic. I’m not sure what would be causing high ph but it never seemed to be a problem in the past until I upgraded to the bigger tank.