Didn't cycle properly, now what?

[lynnec]

I'm hoping you can help with my query. I recently upgraded from a 25litre tank to a 90 litre tank. When I set the smaller tank up I now realise I must have done a fish-in cycle with some danios. I was lucky in that I never had a problem with the water quality in that tank. When I came to set up the 90 litre tank, I did exactly what I did with the smaller tank, ran it for a few weeks to let it "cycle" (I know, I know …) and then put 2 Rams in. Within 5 days they were gone and having read up on cycling I now feel a bit of an idiot and also really bad about what I put those fish through. Anyway, my question is what do I do now? Should I go back to the beginning and restart adding the ammonia as per a fish less cycle or am I already part way through the cycle having added fish? I've read so much in the past few days that I feel I'm going round in circles! I tested the water with my API kits yesterday and Nitrate was 20, Ammonia 0.25 and Nitrate 0. I did a 20% water change and checked it again today and nitrate was 5.0, Ammonia 0.25 and Nitrite 0. I have an internal filter and heater. The tank has gravel but no live plants as the ones I bought I found to be rotting, and I know now this can cause a rise in Ammonia. I would appreciate any advice given as I try to get my head around all this! Thank you.

 

[Tmar]

I would go back and start adding ammonia for a fishless cycle

 

[Rivercats]

It sounds as if the tank is already cycling as your having increasing nitrates but I would get some pure ammonia and dose to 4ppm and see what ammonia, nitrites, and nitrates are in 24 hours. This will give you an indication how much beneficial bacteria (nitrosomonas and nitrobacter) are already in the tank so you get an idea how far along the cycling is then just continue with ammonia and fishless cycling until your tank can process 4ppm of ammonia down to 0 ammonia and nitrites within a 24 hour period. You already have a jump start with your cycling so it may go a lot faster.