I was hoping to come on these forums after Christmas and share about my wonderful 3 new tanks but instead I'm really needing help. I will update my info soon ( haven't had chance yet) but here are the details: Tank 1 5g mini-bow for daughter, tetra whisper internal filter 2-10i, regular gravel, silk plants: male betta, 1 tiny otto, 1 apple snail ( orginally had two tiny ottos but one died). All get along great. Tank 2 5g glass, tetra hush 10 filter, eco-complete, driftwood and fake plants ( hoping to put real in soon): male betta, two very small peppered cories ( baby size). All co-habit very well. Tank 3 10g glass regular size: tetra hush 20 and tetra hush 5 filters, carib-sea instant aquarium moonligt sand for freshwater, driftwood, fake plants ( hoping real soon): 1 dwarf blue gourami, 4 small harlequin rasboras, 2 small peppered cories, 1 medium bronze cory. All seem happy. Heater in each of them. I don't see any signs of stress other than my one betta has fin rot - and came with it. I uses tetra safe start to supposedly cycle each tank. I set tank 1 up first and at the end of 7 days I tested the water and found .25 ammonia, 1 nitrites 0 nitrates and my dead otto and my betta's fin rot looking worse. I assumed the TSS did not work and began daily 50% water changes with Prime. I have done them now for four days and before today's water change the readings are: just under .25 ammonia, 0 nitrites, 0 nitrates. All fishes been fasted for 24 hours too. Edit: tank 1 ph is 6.4-7.4, tank 2 and 3 are 7-7.4 On tanks 2 and 3 after two days of TSS, fish and no substrate, my substrates finally arrived and I added it to the tanks. Fish looked much happier. Then, 7 days with TSS I found both to have ammonia at 1ppm and 0 nitrites and 0 nitrates on both of them. Again, I assumed the TSS failed so I also began 50% water changes on both of them using prime. This is now the 3rd day of daily changes with prime and yet my aminia is still reading 1ppm and nitrites and nitrates. I know I overfed them for a while - I am new to feeding fish other then bettas and messed it up. I have fasted them for 24 hours now. I originally had snails in all tanks but pulled them out as I was seeing them poop a lot and they are in their own temp tank now. I have used TSS in the past with awesome results so I don't know what I did wrong. I feel like I suck at this and wondering whether just to return all the fish and sell my tanks. I tried so hard to get it all right...you know looked into everything carefully, got a great heater and substrate for them...ach! Now it looks like I am cycling with fish which is heartbreaking. I'm testing the water several times day and waking up at night to check on the fish - I'm totally stressed out. If anyone can tell me what is happening/where I went wrong and what I should do I'd really appreciate it. Shouldn't I be seeing a reduction in ammonia by now and some nitrates? I am using API master test kits. Thank you so much for any thoughts.