I started a 75 gallon tank well over 3 months ago. I put a few live plants and a few fish to get the cycle going. The water temp is 80, and I use two filters. One is a canister and the other a bio wheel. After 2 weeks the PH and ammonia were still high. The fish were not eating and one by one died. Which I chalked up to the cycling.
At this point I started a second tank that was 30 gallons. They have the same decor and gravel except it does not have any live plants. During the cycling process the fish would eat unlike my other tank, only one fish died during the process. It took two weeks but that tank was doing really good.
But my first tank still had a high PH and ammonia( this was going on a month now). The store I went to suggested "Neutral Regulator" to bring my PH down. At this point I had no fish left in my tank. I put the substance in my tank and after two weeks the PH was about 7.5 with a lot of ammonia. I then put in a wood log, it was suggested that it would help keep my PH down.
My ammonia was still a bit high, so another pet store told me to get this chemical that was suppose to lower ammonia. I used it once and decided that if it didn't work I would just have a tank with nothing but plants. It took a month but the ammonia finally went away. During this time I was doing 20% water changes a week.
I decided to put fish back in my aquarium since the PH was 7.2, no ammonia/nitrate/nitrites. I have been trying to go slow buying 2-3 fish at a time. Getting tetras and rosy barbs. They will eat well for the first couple of days then quit eating. Then sit at the surface or in a corner with little movement. Half of them have died and the other will not last long since they will not eat. This has been going on for over a month.
My other tank is still doing good, all this fish are doing well with a big appetite.
So I do not know why I got one aquarium to do good and the other I can not seem to get it right. Any suggestions would be greatly appreciated.