I've almost had my tank cycled three times now and every time it gets close, one of my Black Moors develops slime patches. I don't think it's related to the cycle but it's probably related to bad water quality.

Anyway, I've successfully treated with a product called ANTISLIME & VELVET which is a broad band anti-parasitic treatment, but I'm also pretty sure that every time I treat with this, it kills all my beneficial bacteria and crashes the cycle.

I'm monitoring water quality very carefully, doing 30% water changes every 3 days, and using a NITRAZORB filter medium if the nitrogen levels get too high.

and the parasites keep coming back!

it seems I'm stuck in a never ending battle.. trying to get the tank cycled and treating a re-occuring problem with slimey fish.

any ideas on how I can solve the paradox?

Are patches of slime the only symptoms? Does the fish flash or scratch itself? If it is purely the slime then this could just be due to the water quality as you say. If the fish seems well apart from the slime then I think I'd concentrate on my water quality for the time being and get that absolutely perfect. Once it's been good for about 2 weeks see if the slime patches reoccur. If they do and your water parameters are excellent then you could think about treating again. Perhaps try a different medication though as if they are parasites and you've used the |Interpet med a few times they could be immune to it. Perhaps try the Waterlife one called Sterazin i think it is?
Incidently what are your water paramters and do you monitor your PH? CHanges in Ph can cause excess slime to be produced so it would be a good idea to monitor it for a while to check it isn't fluctuating.
I've used ther INterpet anti sime and velvet before and it didn't crash my cycle. Is there anything else you're doing that could perhaps be to blame for this? DO you rinse your filter media in tap water perhaps, do you use a dechlorinator? DO you temperature match your water at water change?

CM, I completely agree with your original assessment as well - it could be due to water quality. I was going to ask if you used anything during the ammonia or nitrite phases of the cycle to help protect your fish (in addition to water changes) and if your pH was stable. Low or fluctuation pH often causes white patches, as FF said, so be sure that isn't the problem.

thanks for both of your comments.

The fish seem fine (apart from more frequent resting and some time with it's dorsal fin down); there's no flashing or scratching.. although there is a little yawning.

I've had problems with pH in the past which I think was the cause of this whole thing starting up, but the pH has been 7 for a little over a week (I've been monitoring carefully). Ammonia is at 2.0 and nitrite below 5.0 so it's not like they're swimming around in ###### but I'm aware that the extended time for which they've been exposed to these higher than trace levels, will have had some effect on their immune systems.

In response to your question about other things I'm doing to help the fish:
I'm running a NITRAZORB filter medium tonight to take the nitrogen levels down further, and I've experimented with "stress coat" to help with the healing process, and salts to balance electrolytes. Anything else I can do?

in response to your other questions:
Q. Do you rinse your filter media in tap water?
A. Never, always a little of the tank water and nothing else.

Q. do you use a dechlorinator?
A. Yep.. a bit of "tap-safe" or "fresh start".

Q. DO you temperature match your water at water change?
A. As close as possible, and I have a heater running at 72degrees which is on all the time.

I have an airstone in the middle of my tank and I'm creating a nice circular current in the tank with my filter which seems to be very beneficial for the filtration (not seen any poo settled apart from their sleeping corner!! - bless - and that doesn't stay long) - anything here sound wrong?

thanks for your help.

Ammonia at 2 and nitrite at 5 are really quite high...trace amounts of either (anything higher then .25-.5) is really harmful to the fish. I would recommend just upping the water changes...to one 40% change a day....hopefully you can get those readings down to zero soon. This is probably the reason for your fish being sick, so I would definitely worry about this as opposed to treating with a medicine.

I agree, increased water changes (or larger changes, if you're already doing them frequently) would help lower the levels. You could also use an ammonia binder (like AmmoLock) to protect your fish from the ammonia while it's present and salt (1.5T per 5 gal) to protect your fish from the nitrites.

If you've been having problems with your pH dropping, that is a *huge* problem - one which could easily kill your fish if your pH crashes. Do you have a KH test to check your alkalinity?

yup.. I agree.. it's high...

I've cut down their food and I'm now on 30% water change per day until the nitrites get down. Ammonia isn't too bad as I've had a NITRAZORB filter medium in there for the past 48 hours, but it doesn't seem to have helped the nitrite levels too much.

I've added slightly less that recommended of the salts as I don't want to mess up the pH too much (my water has no buffer!).. pH is now stable at around 7.2.

Bif looks like he's taking it worst. He's lost a couple of scales and was hanging yesterday with his dorsal fin down. He's looking a bit perkier today though so fingers crossed, everything should be okay.

I'm worried about putting all that fresh water in there though.. will the beneficial bacteria be able to handle the drop in organic matter?