[vaporize]

Hi Lee,

Hope everything is going well, I got another tricky case on my hands it seems.

As you might know, I have been trying to read as much as I can from your disease forum and this is one of the greatest asset on fish health and disease in the internet. And I have encountered my share of diseases. Having said that, I would think I am pretty familiar with the velvet disease (Amyloodinium).

Not so recently this happened in one of my clownfish collection system. All the fish that goes into this system goes through a standard quarantine period of at least 4 weeks to max of 8 weeks, and I only transfer them to this system when I am pretty sure they have no signs of disease.
- around 60G total water volume
- barebottom with LR
- some hermits/snails for cleanup crew
- 11 different types of clownfish but all seperated housed by species
- top & bottom tanks with return pump & heater
- pots for breeding & hiding
- ammonia 0, nitrite 0, nitrate ~20
- there are isopods on glass (not sure if it mean anything thou, might just be from LR)

About 3 weeks ago, I started to see signs that looked exactly like velvet disease. A bit faster breathing (but definitely not as fast as the newly arrival velvet victims), alot of dusty white spot covering the body, scratches of the gill against glass/pots, some loose of color, some fish has cloudy eyes. This does not show up in all fish at the same time, only 1 or 2 at a time. Most of them continues to eat a variety of food (NLS pellets, ON formula 1, flakes, mysis).

All the signs tell me that it is very likely to be velvet. However also from my previous many episodes of velvet, usually by the time I see such dusty white spots covering the fish, the fish should die within 0.5 day to at most 2 days (if they do not recover from cupramine treatment etc). However durin the last 3 weeks, I see some 'white dusty' covered fish come back to its full black color after 1.5 weeks. And since the first observation of the symptoms, it has been 3 weeks+ and I have not lose a single fish (some fish do show signs of uncomfortable), and the original infected one seems to recovered. There are no killing of the parasite if it's velvet since there is no UV in this system (maybe a few small sponge on glass).

I would like to check with you to see if you would suggest anything else, I would not like to dose my clownfish collection system with copper unless I really have to, since it might sterile them for awhile. At this moment, all I can see is that the disease can be transmitted from water, so only yesterday I added an 18W UV into the system.

Thank for any insights.

[leebca]

You are a good customer for this Forum, Vaporize. Though I wish you weren't in need of the help, I appreciate your gratefulness. You seem to have been through quite a bit.

You are correct, in general, about the speed at which Marine Velvet (Amyloodinium ocellatum) kills.

I'm afraid this one requires some visual. I need photos of what it is you're seeing. True MV doesn't go away. Yet there are other parasites that mimic some of its symptoms yet aren't as lethal. Unfortunately, besides photos, it is almost necessary to take scrapings to identify the likely culprit.

Your experience with these fishes has got you to the point where you can recognize when they are 'uncomfortable' or bothered by something. That is very good on your part. It is almost like a sixth sense. You get to know the species and when you study a fish for a while, you can tell something is irritating it. But, I digress.

If what I've read is correct, you have not suffered any fish loss due to what you're seeing. If that is the case, then I'd leave everything alone and use the UV to its full and proper potential.

The cloudy eye can be a secondary or primary symptom. If it is secondary, most likely it is from bacteria. The UV may help with that. The presence of the pods indicate the presence of bacteria, microbes, or micro algae (most pods eat one, two or all three). They can be cannibal/carnivores too, but that just means there must be something lower on the food chain living off micro organisms. I'm not enthused about you using live rock in a breeding setup. It introduces a lot of variables when it comes to marine organisms.

Next is cleanliness. Make sure the system is free of detritus and organic wastes. Do you have a skimmer on the system?

Lastly, verify the amount of circulation you have. Make sure you're getting no less than 10 turnovers per hour and each section is getting its proper circulation.

That's about all I can say without additional information.

[vaporize]

Thanks Lee, I will try to do some big water changes to siphon off wastes and detritus. As there is no skimmer on the system. I have two other system that leverages a large amount of marco-algae for nutrient exports, but this one does not have the same HOT5 lights so macros does not furish.

At this moment, I am not sure if the fish is 'always' able to recover or not. But I suspect b/c they have been living in captive condition for awhile that they are alot more hardier than new arrivals.

Will try to get some photos tonight (when my camera girl) is back.

thanks again for all the help

[vaporize]

Hi Lee, seems like my dummy digital camera can't get a clear enough picture to show the light white patches & dusty dots. However it's almost another week passed, and the fish are a bit better appetite after I put in the UV. However the dusty white spot & white patches still exist.

I was reading on some forum threads that in large scale systems, it might be more cost effective to use ozone as suppose to using UV in killing free floating parasites. Just wondering your thoughts on this approach?

It might be better for my multiple clownfish system.

Thanks

[leebca]

That ozone kills parasites is more a myth than fact. Think in terms of size:

Virus (smaller than)
Bacteria (smaller than)
Microbial Pathogens (smaller than)
Amoeba & similarly sized Parasites

The UV if properly sized and the flow rate controlled will kill the parasites of the Amoeba class and smaller. The ozone treatment kills Virus, but almost nothing larger.

Now think in terms of how many are killed. The volume of tank water that passes through the UV is far greater than the volume going through the ozone generator. So the ozone kills very few Virus; the UV kills a lot of Amoeba.

In short never use ozone to try and control pathogens.

The value of ozone is water clarity and changing proteins the skimmer doesn't get out, to proteins the skimmer can more easily remove.

White patches are first and foremost a water quality matter that leads to secondary bacterial infections. From all past problems I'd say the water quality is the issue. Verify you have no dead spots in the system (circulation) and perform larger more frequent water changes for the time being. Water quality should of course include zero ammonia, zero nitrites and perfect water chemistries, but it also includes things not checked by test kits: What is Water Quality