That salt can also retard the blooming of velvet, a pesky parasite usually in a tank at a non-lethal level. When it blooms it can take out guppies and Ancistrus. The tough part of the attacks on Ancistrus is that they don't get it much on their armored bodies, but their gills are very vulnerable. Then they suffocate. I fear that I lost my breeder females (several years ago) to that, having fed them too exclusively on brine shrimp pellets.

Also, do you know if your bristlenoses are wild stock or raised in local aquariums? Ancistrus and some closely related genera are among the suckermouth catfishes (Loricariids) which spawn pretty regularly in aquariums and fish farms.

But there are a lot of Ancistrus species, which are wild caught and new ones are being discovered. And fish farms may have their shared of parasites too.  ALL wild suckermouth catfish come in pretty starved and stressed. That also means that they will be covered with some sort or sorts of parasites. Somebody - wholesalers, pet shops and probably us as final consumers - MUST treat for parasites. If we don't, many of them will "mysteriously" die and probably take other fish with them! Treat them in quarantine. If you do not treat them in quarantine, odds are pretty likely you will have troubles with their health.

I discovered a problem in feeding my young golden bristlenoses recently. Had picked up a small zucchini at the farmer's market, put it in the microwave for a minute (to blanch it), let it cool, sliced it into small pieces and froze it in a zip-lock bag. When a piece was defrosted and fed to the 10-gallon tank of bristlenoses, the water got cloudy in a hurry. The bristlenoses must have eaten their fill. The snails were shaken from the fragments of zucchini and the fragments were removed. A 50% water partial change immediately followed. Feeding stopped until the water cleared a day later.

I used to "get away" with feeding zucchini before to my breeders and youngsters in their 29-gallon tank. So what were the differences? Obviously there was the tank size. Also in the 10-gallon I have small disc-shaped sponge filter. It looks something like this: (3rd down) http://www.aqualandpetsplus.com/Misc%20Sponge%20Filters.htm

In the 29 there was a much larger Hydro sponge - probably something like this http://www.kensfish.com/files/hydro__2.jpg

The other thing about that 29-gallon tank was that after a while I put gravel in there. That added a lot of surface for beneficial bacteria. A new book on problem trouble shooting (review to follow some afternoon) by TFH editor David Boruchowitz (who is becoming something of an aquarium book of the month club single-handedly) makes the very profound point that the ENTIRE AQUARIUM is a biofilter. By adding the gravel that increased the ability of that tank to biologically break down the goodies produced by that zucchini and the fish that ate it.

In fact, Boruchowitz has put a very profound spin on cycling an aquarium. He suggests that cycling an aquarium is essentially maturing the biofilter. And that biofilter is not only the "filter" but the gravel, decorative rocks, plants (real and plastic) and any other surface in the tank.

Such a simple but elegant thought! (So why didn't one of us think of it...?)

As for that 10-gallon with the Gambusia vittata and the bristlenoses? As soon as a zillion other more pressing things are done, there will be a layer of gravel added, even though I will then have to take a gravel vacuum, rather than just a siphon hose to that aquarium at least weekly. The bristlenoses are getting algae tablets. When the gravel has been there a couple of weeks, smaller hunks of zucchini, rather than just the harder algae pellets will be added.

As for your tank, try picking up the partial water changes. Add surface for your biofilter, if possible. Be careful not to overfeed.

If you feel that your bristlenoses must be medicated with an antibiotic, move them to another aquarium, bring a lot of their water with them. Add a box filter with some rocks to hold it down and aerate briskly. If you have access to an anti-parasite treatment with Flubendazole in it, I would use that. Every couple of days, add 50% "new" water. If that water can come from a healthy, established aquarium, so much the better. When treatment is done and the plecos are looking better, switch them back to their home aquarium.

I'm glad you brought this up. We often don't realize what can be brought into an aquarium with new suckermouth catfish.

I was a little surprised when you mentioned that searching Guppylog got you nothing. I tried the Google search, having checked the Guppylog box and got well over 200 hits for fin rot. However when I tried it a little later, nothing happened. (Sheesh!) Googling Guppylog and fin rot got about 9 hits, a few of which were indeed from Guppylog.

There are still the Finrot/Split fins/Tailrot/red fins entries in Immediate Help and I would urge everyone to start their searches there., But you are correct, searching Guppylog is sometimes very frustrating.

I'm really sorry that you lost the bristlenoses. If you wish to try them again, look for a local aquarium club auction. (Google your area and Aquarium clubs or aquarium societies. Check their sites for calendar info.) Those fish will be more accustomed to local water and far less likely to be loaded with the Pet Shop's resident parasites.

And please consider a 10-gallon quarantine tank with a box filter or at least an airstone, submersible heater and a few plastic plants. Maybe include a glass cover. If you have an aquarium on one of those metal stands, you could house it on the lower level. That is an expense, but if you have had two wipeouts of fish in your aquarium, you have already spent more on dead fish than what that quarantine tank will run you.

Buying pets can be like that. After we paid a $100+ donation to a dog rescue group for our schnoodle, we spent more on him at the Vet's that first summer than we spent on our entire family at the doctor's. New pets will have hidden expenses like that.