To Uv Or Not To Uv?

[Jabba]

I have been hit by the dreaded Ich - (at least I think it is - sure looks like it) - despite 8 months of total stability and happy fish I have lost 5 fish in as many days, the silver dollars are covered in tiny white spots. The swordtails are dropping at the rate of one a night and seem perfectly healthy one day with no visible signs and then they are dead in the bottom of the tank in the morning, my male Betta died, 4 Neon Tetra have disappeared.

It has started since I introduced 2 Bala sharks and 2 Chinese Algae Eaters into the community after they spent 14 days in the quarantine tank with zero problems.

Initially I thought fungus because one of the dead neons was like a ball of cotton wool, the other three I have never found despite removing all decorations to search, the sword tails faeces is white and stringy and they are clamping their fins a lot, but they are the only inhabitants who are - so this has to be some sort of bacteria or Hexamita I think - I sure hope it isn't some other parasite - but the white spots would indicate Ich not Hexa but not all fish seem to be affected - some not at all (at least that is how it appears).

My water stats are Nitrate below 5ppm, PH is 6.6 ish, Ammonia and Nitrite are both zero, this I check on a daily basis. Temperature is 25 degrees, tank is 215 litre with approx 2000 lph filtration through a hood filter system and an external fluval. There are no live plants in the tank due to the behaviour of the silver dollars making it too expensive. I do a 25% water change weekly using a Python to do it and therefore vacuuming the cleaning the gravel during the water change, at the same time I clean out one of the three filter trays in the hood, the Fluval is cleaned once a month, the ornaments I remove and clean monthly but two weeks after the Fluval. I have less than 20 inches of fish currently in the tank so it is probably a bit overfiltered but can there aver really be too much?.

Despite everything still I am hit by this 'problem' I find myself asking if I am doing enough, is there more I could do?

I have read mixed views on the use of Ultra Violet Sterilisers in tropical aquariums many say they are of no value a few say they are worth it. One LFS says that UV won't kill the Ich in the swimming stage and two who say it will, and in any case will help with any secondary bacterial or fungal issues.

I know it won't cure but is Ultra Violet a worthwhile preventative / assistant in the tank. If so I am going to replace the overhead filtration powerhead and the Fluval with an AquaEl Unimax 500+ combined filter / UV unit (to maintain the flow rate that the current overhead filter has), the cost is irrelevant, the well being of the fish is number one.

What do the team think?

 

[rdd1952]

A UV Sterilizer will kill all free floating ich organisms. Actually, it will kill anything that passes through it whether that be ich or vloating algae such as diatoms (they work great on green water). Unfortunately, it won't help rid the tank of the outbreak you have but should prevent it frm coming back except if you introduce it with a new fish.

Ich organisms are present in the water all the time and just need some stress in the fish to kick it in. The sterilizer will kill all free floating ich so that introduction from an outside source is the only way your fish can get it.

 

[andywg]

Ich organisms are present in the water all the time and just need some stress in the fish to kick it in.

"Utter rubbish!"

Read the Skeptical Aquarist's page on ich, most notably the below (my bold):

Dr. Peter Burgess, who took Ichthyophthirius multifiliis as his Ph.D. subject at Plymouth University, mentioned among Ich "old wives' tales" that "It's present in all aquariums." "What utter rubbish" noted Dr. Burgess (in the Nov 2001 Practical Fishkeeping).

 

[rdd1952]

I read the article and I definitely don't profess to know anything about the scientific side of it, only what I have read elsewhere but if the organisms are not present in the water at all times, how do tanks that have been running or months or years without any problems and with no introduction of new fish or plants suddenly get hit by an outbreak of ich? Is it possible for fish to carry the tomites on their gills for months on end without any outbreaks. I guess even then though it would be stress that makes the fish susceptible and sets it off.

 

[Meds081603]

I read the article and I definitely don't profess to know anything about the scientific side of it, only what I have read elsewhere but if the organisms are not present in the water at all times, how do tanks that have been running or months or years without any problems and with no introduction of new fish or plants suddenly get hit by an outbreak of ich? Is it possible for fish to carry the tomites on their gills for months on end without any outbreaks. I guess even then though it would be stress that makes the fish susceptible and sets it off.

My understanding is it has a life cycle of 14-16 days if it can not find or attach to a host. I know people often use the same nets and or cleaners on multiple tanks. In this way it is possible for a tank thats been running for years with no new fish to get ich from another tank without realizing it.

 

[Bignose]

Is it possible for fish to carry the tomites on their gills for months on end without any outbreaks. I guess even then though it would be stress that makes the fish susceptible and sets it off.

Yes, very much so. Fish can be asymptomatic carriers for quite a long time. That is possible. And, if in treating the tank from a previous outbreak, one single organism survived, it may have taken several months before the population grew back to symptomatic levels.

But, time, and time, and time again, the ich organism is studied in the scientific literature and no dormant stage has ever been reported. Ich is studied a lot since farmed fish get ich, too, and they can't use the powerful medicines we use since those medicines make the fish unsafe for consumption. I would think that all the experts whose job it is to study fish parasites would have found a strain of ich that has a dormant phase by now with all the study the ich organism has undergone. But, none has been found. Yes, this isn't perfectly 100% conclusive evidence that a dormant phase doesn't exist, but in exactly the same way, it certainly isn't proof that one does, either. And, since all the evidence to date has pointed in one direction, and one direction only -- no dormant stage -- chances are exceptionally good that a dormant stage does not exist.

Meds, ich's life cycle is a strong function of temperature. At tropical temperatures, the life cycles is as short as 3 to 4 days. At koi pond temperatures, the life cycle is as long as 30 or even 45 days. Back to my first paragraph here, because if a single organism escapes the ich could come back, seemly out of nowhere -- seemingly from dormancy, I always suggest using medications through at least two full life cycles and three if the fish can handle it. Better to expose the fish to a few extra days of medications than to let a few ich escape and restart their infection to become full blown infection a few months later. For tropical tanks, I suggest at least 8 days and ideally 12 full days of medications. You can be much more confident that every ich is killed that way rather than just dosing for 1 or 2 days "after the spots disappear"

Oh yeah, I have to address the OP's question about UV sterilizers. Sterilizers are very good at decimating populations of bugs/parasites/algae etc. But, and this is a big but, it cannot destroy 100% of the problem. This is simply because UV sterilizer cannot treat the entire tank at once. Only a small portion of the tank's entire volume is treated at once. Yes, the entire tank's volume is turned over x times per hour (3, 5, 10 times per hour, whatever), but because the return is mixed back in with the original tank water, there is always some water and hence some tiny fraction of the population that does not go through the UV sterilizer. Compared with medications, since you dump the meds into the tank -- they treat the entire tank's volume at once. There is no place to hide, in other words.

Now, like I said, UV sterilizers are good in terms of reducing the population of the ich down to like 1% or 0.1% of it's original numbers. But, the UV cannot ever get that number down to 0%. What is a great course of treatment is to use the UV for a period of time, again to decimate the population of ich. Then, take the UV out, and use medications as the knock-out punch. Again, because medications can treat 100% of the tank, leaving nowhere for the ich to hide. And, again, just like I said in the first half of this post, if you don't get the population down to 0% -- complete and total eradication -- that ich could come back. And that is the last thing we'd want.

 

[Jabba]

Thanks again all,

Well right or wrong I have ordered an AquaEl filter with built in UV.

My tank temp is currently up to 27°C, I have under substrate heating and it isn't as fast as those horrid glass things ;-) , I lost no fish last night and things appear improved so I will continue to dose the tank. I will continue to dose for at least another week then I will do a water change and install the new filter and UV. I have deliberately oversized it and will be able to do at least 4 complete tank changes an hour. Given that the Ich swimming cycle can be a few hours that sure can't hurt anything but the Ich.

Anything that helps is better than nothing at all and it seems that UV can only help in such situations, I only wonder now why so many places I have read seem to treat UV with some sort of 'snobbery' i.e. you only need that if you can't do the job right .... well to those people all I can say is enjoy your time in the cave because based on everything I read about UV in Marine tanks and even domestic / industrial applications, even at NASA it certainly can help reduce water borne pathogens and bacteria etc so why not use it.

 

[andywg]

Anything that helps is better than nothing at all and it seems that UV can only help in such situations, I only wonder now why so many places I have read seem to treat UV with some sort of 'snobbery' i.e. you only need that if you can't do the job right .... well to those people all I can say is enjoy your time in the cave because based on everything I read about UV in Marine tanks and even domestic / industrial applications, even at NASA it certainly can help reduce water borne pathogens and bacteria etc so why not use it.

It can help, but if you take precautions to prevent a problem, then a cure for the problem is superfluous.

UV treats the symptoms (the ich in the tank) more than the cause (a fish or plant carrying the pathogen being brought into the tank).

UVs are particularly recommended for centralised filtration systems to prevent ich (and other ills) spreading from one tank to the rest of thet anks in the system. I can vouch for how quickly they will decimate an outbreak of ich, but I would definitely recommend turning off the UV and then treating for a couple of cycles as bignose says, just to be rid of the ich.

 

[Jabba]

but I would definitely recommend turning off the UV and then treating for a couple of cycles as bignose says, just to be rid of the ich.

Which is exactly what I plan to do should the need arise in future ... and in future any new arrivals get 28 days quarantine and get treated for Ich and fungus etc while in it - whether they show signs of infection or not, and don't worry I do realise UV is not a cure for correct management etc.

 

[Meds081603]

I understand that temperature is what affects the duration of life cycle. I understand there are different strains that are affected by it's environment in eifferent ways.I don't see ich ever having a life cycle of 3-4 days at tropical temperatures for any strain though. I have had tanks hovering close to 90 degrees that showed visible ich for 3-4 days. I have also had tanks with that high a temperature where I lowered it too quickly after the spots disappeared. When I drop the temp too early sure enough the ich WILL come back at some point. I have never heard before of the life cycle being only 3-4 days under any circumstances. I agree with everything you have said and much of it has been proven but could you share where you have received some of this information regarding such a short life cycle?

 

[jasonskillz]

just get a UV, its worth it.

 

[Bignose]

I understand that temperature is what affects the duration of life cycle. I understand there are different strains that are affected by it's environment in eifferent ways.I don't see ich ever having a life cycle of 3-4 days at tropical temperatures for any strain though. I have had tanks hovering close to 90 degrees that showed visible ich for 3-4 days. I have also had tanks with that high a temperature where I lowered it too quickly after the spots disappeared. When I drop the temp too early sure enough the ich WILL come back at some point. I have never heard before of the life cycle being only 3-4 days under any circumstances. I agree with everything you have said and much of it has been proven but could you share where you have received some of this information regarding such a short life cycle?

There is a preponderance of evidence that at tropical temperatures, the life cycle is 3-4 days. From Skeptical Aquarist's page cited above in andywg's post, several times it is mentioned "a few days" which I take to mean 3 to 5,

From Bugess, Bailey,and Excell's Tropical Fish A-Z Talking about an tank with no fish that has ich in it: "Under tropical conditions (above 21 degrees C) the aquarium will generally be white-spot free after 4 days, though it is best left for 7 days to be on the safe side"

The article on cichlid-forums.com ( http/www.cichlid-forum.com/articles/ich.php ) recommends quarantining new plants for 5-7 days, just like the above source so that more than the ich's entire life cycle has passed without finding a fish host so it will die.

There are many more examples. I don't have it in front of me, but I read a review paper (in a scientific journal) describing everything that was known about ich to date (2004 I think) and they quoted the life cycle as 3-4 days at 90 degrees F. I'll look for that paper later tonight if you really want me to find it again. (I cited it in an old post here, but these days that's a lot of posts to go through).

But, the point is, there are lots and lots of evidence that at tropical temperatures, ich's life cycle is 3 to 4 days.