Looking for cycling advice

[tlyons01]

Ok, short story is that I had cycled completely, 2 tanks. 10 gallon divided and a 5 gallon. I decided to get a 6.6 gallon, divided it as well. I have had the 10 and 5 running for almost 3 months now, taking care to not clean off too much bacteria with each cleaning and PWC. The boys that are housed in these tanks have been going up and down with fin damage and loss of color, etc. I had been checking my water parameters when I saw signs of stress and all, with readings where they should be for 2 of them, and one had all 0's. I have just removed them all to QT tanks for the time while I went ahead and tested the 5 and 6.6 gallon with pure ammonia. After 24 hours, the tanks both still had ammonia readings.

First, I would like to ask your thoughts on the following:
Would a fully cycled tank lose too much BB due to only containing one betta? and what about 2? I know that they can't produce as much ammonia as the BB gets built up for using pure ammonia, so it made me wonder why one that was cycled, would not be now...
Second, is it not possible to keep a cycled tank under 10 gallons cycled? I tried with a 2 gallon in the summer, but read about the surface area not being enough to keep the cycle without fluctuating readings. Does that apply here too?
What should I do now? Should I just do a full water change and start over, fishless cycling? Or just keep dosing the current setups with ammonia and proceed with fishless? Or put them back in and increase the amount of PWC and time between them as to not stress them out? I just don't know what to do from here forward. Any advice or previous experience that anyone feels like sharing would be greatly appreciated, thanks!!

I guess I should add that both setups have filters and heaters and all.

[Oldfishlady]

What kind of testing product are you using...do you have live plants in the tanks, type of filter...Bettas the only livestock...

If you are still testing 0ppm on the nitrate....your biological filter has not been established.....

What is the pH....

You can only establish enough BB for the current livestock...any extra-the BB with start to consume each other.....

If your finial stocking plan is just the Bettas and maybe some shrimp and/or snails....I would do fish-in cycling....you can safely do this provided that you make the needed water changes....

[tlyons01]

Hello OFL, thanks for responding. The testing products I use are the API drops, and each has the HOB filter, one also has a sponge filter (on one side of divided). The final inhabitants would be Bettas only, at least for now, for sure. I would like to add shrimp or frogs once I know that I have this water thing under control. I had thought that the BB would die off after creating so much of it, didn't know it would eat itself though!

I must have done something wrong with the tested tank that read 0 nitrates, because water has 5ppm right out of the tap! I have an anubia in one of the tanks, and only silk in the other. Have anacharis but moved it all to a planted tank for now to get them growing well. I was afraid the plants were causing issues, and I used root tabs in the one with them, so I was trying to basic it down.

My PH is always the same 7.8. I have never had any different readings for that..

Thank you for your advice, I will increase the water schedule and check my params every week for the next few months. Have a great day!

[Oldfishlady]

That is odd getting 0ppm nitrate in the tank when you have 5ppm from the tap....live plants can use the nitrate for food.....but still odd...

Make sure you give the #2 nitrate reagent bottle a good shake, bang and shake some more....it tends to settle and can give skewed readings....with the API nitrate test in general...if you don't follow the directions to the "T" you can get skewed results....for some reason the nitrate API has a high rate of user error.....I sometimes have to repeat the test and I have been using this products for over 10 years at least...lol....