Okay, this is a quickie. Benvolio Bashir Betta is doing great, so far as I can see, but (as I said before) he does not like his palm filter. Put a big silk plant in there, and now he's happier, since some of the current is blocked, and is back to making bubble nests. I do feel strongly that every fish should be living in a filtered tank, if at all possible, but-

Is it really possible to cycle a 2 1/2 gallon tank? Or will I need to do occasional complete water changes, in spite of the filter? So far I've done two water changes, taking out a gallon each time, and his conditions seem pretty stable. But it won't be too hard to completely change such a small tank, obviously - so do I need to do it? If so, how often? I thought maybe once a month?

TIA for your help!

Even if you keep it filtered you will need to do partial water changes once every one if not two weeks till the (bio) bacteria settles in stable params.

Well - thanks, but I do know that. I have been doing pretty large partial changes every week, as I said, and that's not a problem, but I want to know if I will need to do total changes, the way you have to in a bowl. Does anyone know?

If not, I guess I'll conduct an experiment and do weekly ammonia/nitrite/nitrate tests before my water changes to see if I can find out if a cycle is happening. From what I've seen of the palm filter (which is exactly the same design, size and price as the Red Sea nanofilter), there's no biological component so achieving a strong cycle isn't likely. Just wanted to know if getting a full cycle was even possible on a tank this small.

I have never tried to cycle a tank less than 5 gallons. I would say that you should test the water frequently to make sure that it does cycle. Please let us know how it goes. I will be curious to see how stable it is.

Exactly as I said, partial water changes. No need for full changes. Do let us know what happens.

I agree, there is no need for a full water change and one can in fact be stressful to the fish...so don't bother. Also...try to keep the tank in a warm spot because it is too small to heat.

You can cycle it - I have 4 cycled 2.5 gal tanks. I also have heaters in the ones in rooms with temps that fluctuate too much (Wallmart sells a heater for tanks up to 5 gal).

Good Luck!

Jenn

well, thanks all - here is the result of tonight's water test:

PH 7.0 to 7.2
ammonia 0
nitrite 0
nitrate 12.5!

Yikes! that looks cycled! If there is some cycle in the tank already, it's due to the live plants, all of which are growing steadily. I've decided to keep up with the once weekly 50% water changes until I see some indictation I need to do more. Everything looks fine for now. Am thinking of adding a clip on light and small heater, especially as we head towards fall - will keep testing and let you know how things go.

Second water test results:

PH: 7.4 or thereabouts (a rise; this was the only change).
ammonia: 0
nitrite : 0
nitrates: 12.5

Dont' understand the rise in PH; maybe offgassing of CO2 from the filter or use of it from the plants? But he seems happy, so I won't worry about it.

(Now that their tanks are next to each other, I've seen him flare at Poly twice. At first I was worried I might stress him by causing him to defend his territory from her, but he actually doesn't flare too much. Will try to get a pic.)