Loaches Online Forum

We've got two slightly too-crowded quarantine tanks, and lately we've been fighting columnaris. Two problems we've had have been a biofilter crash and also thermal stability with the little 50 watt "Elite" brand heater. All these new fish have been exposed to either too much temperature variation or ammonia spikes or both, and over the last couple of days what's probably columnaris has showed up.

It seems to not be spreading with furan-2, which is good. Last night a tiny bit showed up on a rasbora hengeli in the little new-guy tank, which was disappointing, and I hesitated to medicate. I figured if we lose that biofilter in that tiny tank, they're toast.

All of my googling had yielded "information" on both sides of the fence -- furan 2 will either kill the biofilter or not.

But, I decided to experiment, and dosed them with furan 2. This morning I tested the water, and indeed ammonia still is zero. So far, so good!

Yes, so far, so good.
Might be a good idea to either culture some bacteria to be ready as a replacement or a boost to the population, or else to buy a bottle of the correct species, and keep it in the fridge, just in case.
At the end of the treatment you will be doing some big water changes to remove the medicine, so you can boost the bacteria population then with no fear of it dying off.

During treatment there is not much that you can do if the bio filter dies.
Water changes to keep the ammonia low, but you will also have to keep the medication level up is probably the best course.
Add things that filter out the ammonia such as zeolyte, but will this also remove the medicine? Most meds say to remove activated carbon, but do not say anything about ammonia removing products.
Add live plants that will remove ammonia and the other nitrogens. This means you will need to keep the light bright enough to keep the plants thriving. Some medicines are light sensitive, though, so this is not the answer in all cases.

Some medicines are OK with established nitrifying bacteria, but do not allow it to reproduce. Over a long treatment the bacteria will gradually die off. Adding more bacteria will boost the population, but these added bacteria also will not reproduce when those meds are in the water.

You can raise your own nitrifying bacteria by doing a fishless cycle in an empty tank, a storage container or a bucket. A 5 gallon bucket is OK for a large canister filter, it can be set up so very little of the water splashes out. Storage containers with flat sides work well for HOB sorts of filters. Simply dumping the filter media in a bucket and adding a small fountain pump will provide enough water movement to support the bacteria. Once you have a reasonable bacteria population you can swap the cycled media for media without bacteria and keep the fishless cycle going as long as you have a hospital tank in need of bacteria.

We have some established media in a LARGE bowl, along iwth gravel and water, and are adding ammonia to it regularly. Also have a bottle of SafeStart on hand...

When I find some I also want to get a big bunch of Hornwort to keep on hand for just these situations (have been looking all along, but none of the fish stores we've tried have had any) Isn't that one of the best low-light plants for removing nitrogenous compounds?

Update -- the gravel and media have now been moved to the 40 gal (with plant substrate and a lot more gravel), so hopefully starting that tank along while waiting to repopulate the q-tanks if necessary.

The little tank with the aquaclear has kept zero ammonia through the furan treatment, and is zero now at the end.

And the furan worked. We did it because one of the rasboras had a white mouth. Everybody's fine in there now.

Plants that tolerate low light are not really thriving to the point that they are good at removing ammonia, nitrite or nitrate.

Hornwort is OK, but I have only grown it well in hard water tanks. Melts in soft or very warm water.

Anacharis, Wisteria are pretty good nitrogen sinks, if there is enough light.

ive been using alot of medication lately.

furan 2
em erythromycin
kanamycin
tetracycline

are all ok for the bio filter. won't crash it.

maracyin 2 will. be careful with this stuff i killed some fish using it by accident in the past.

ive started going the route of medicated food now. and keeping the water clean. much less to worry about.

Medicated food seems a much better way to go. You are targeting the disease instead of the whole tank. As long as the fish are eating, this is good.