I've been doing a fishless cycle. Last night there were pretty many nitrates in the tank, but the nitrites were still off the charts (I think I overdid it a bit with the ammonia) and this morning it finally finished off the ammonia. I'll keep adding ammonia to feed the bacteria until I get a fish, but I have some last minute set-up questions.

First, I have a small, pretty useless filter from before I knew better that I've kept in the tank in case it had some good bacteria still in it. Will removing it from the tank mess up the cycle at this point? My other filter (AquaClear20, I think) has been running for about a month now, so hopefully it has enough of its own bacteria.

Can my filter provide enough airation, or should I hook my air pump back up? I can see my one plant waving from the current and there are bubbles in the water from the filter flow, so it seems to be circulating the water pretty well.

I'm worried one of my plastic plants is too pointed for my future fish, especially since I might be getting a moor. It isn't sharp or hard, but the edges are still pointed (like pine needles).

Finally, I know I need to change most/all of the water before getting a new fish, but should I add any salt? I've heard it can help keep new fish from stressing, but I don't want to kill all the bacteria I just grew. Should I add some now, to get the bacteria used to it, or not use it at all?

Sorry for all the questions, I just want to make sure everything's perfect when I get my new fish.

Oh, and if it's important, it's a 10-gallon tank with flourescent lights, plastic plants, one live plant (some type of sword), and 100gph filtration.

Congrats on almost completing your cycle! While there are some BBs on your old filter, I'd go ahead and take it out now if you don't plan on using it when you have fish. It might slow you down by a couple of days, but better that happens now than when there's a fish in there. I didn't notice much of a bump at all when I took out my "seeding" media, but I suspect that every case is different.

I would worry about the plastic plant just because your tank is already the minimum size and because it could be pointy. If you're not really attached to it, why not take it out so that you don't have to worry? Also, that way if your fish develops ragged fins, you'll know it wasn't from the plant. You can always add it back in later once you know everything else is stable. The bubbles are probably up to you since your filtration is sufficient.

The salt can harm your BBs, but is less likely to if you add it gradually. Any sudden change of temperature, pH, or salinity can affect your cycle. Since you have a live plant in there, it's probably not safe to go over 0.1%- 1 teaspoon per gallon of water. Make sure you measure how much water your tank really holds, as my 10 gallon tank only holds 9! You can add up to 0.1% safely without killing your cycle.

Many people recommend higher doses of salt for new fish, but be careful if you go over this level, because salt can be stressful for a small fish, and you'd probably have to take your plant out if you go over 0.1%. That's considered a "tonic" level- it won't cure anything on its own, but it can help your fish take in oxygen and handle any nitrite bump that comes from adding the fish. Also, remember that salt doesn't evaporate, so only replace what you take out through water changes If your fish has any "issues" from being in pet store water, it would be best to post in the diagnosis board to get recommendations from a mod before increasing the salt.

It sounds like you're off to a great start! Have fun fish shopping!

Thanks a lot! The small filter and spiney plant are both gone now (and it does make the tank look like it has a lot more swimming room). I also added a teaspoon of salt, 1/2 at a time. I don't want to bother the bacteria and have to start again. The tank holds about 8.5 gallons because I have too much gravel. Once I'm confident the tank is stable, I'll start taking some out a little at a time.

I have another question now: The ammonia is completely gone again, and when I checked the pH it had dropped from its usual 7.5ish to around 6.2. I'm guessing this has something to do with the lack of ammonia, since it's very basic? I'm trying to remember my chemistry, but I never really liked that class. Anyway, I used a pH increase because I was worried about the sudden drop harming my plant, but is there any way to bring it up and make it stable? I've never seen my pH that low before, I think it's about 7.2 out of the tap. I'll do another test tomorrow, I'm rationing my remaining strips until I can get to the store.

Once your cycle stabilizes, your pH should too. You can always do water changes to bring the pH back up if you're worried about the plant.

Thanks again. I can't wait to be able to get a fish. But in the meantime, my Ph and KH keep plummeting, and the nitrites are too high for my test to even measure anymore. I did a waterchange, and I'm about to do another one, but is there a certain Ph level that will kill these bacteria I'm trying to colonize? And also, how long can these bacteria survive without any ammonia (ie. can I not feed the ammonia bacteria for a day to let the nitrite bacteria catch up)?

I think that the bacteria are more hardy than your plant, so the water changes are a good idea. I'd keep feeding the ammonia, but maybe in as small a dose as you can manage to put in.

Thanks again! I'll try that. I don't know what I'd do if I hadn't found this site.