Hi, just recently setup my aquarium about three months ago. I started off with a little starter fish(not african cichlid) and a pleco. They both lived in my aquarium for about a month and a half. Then I decided to start african cichlid tank. I started out with adding three african cichlids. Then two weeks later I bout another two african cichlids along with a test kit. I have owned aquariums in the past and never tested the water and I have had them workout on their own for two years. This time, I decided to get a test kit. When I tested my water the first time my amonia level was around 0.50 ppm and it ihas slowly risen to between 4.0-8.0ppm. My nitrite level is 0ppm and my nitrate level used to be very high ( 40-80ppm) but it has dropped to 0ppm. My PH is around 8.4. Currently I still have the pleco, and five afrcan cichlids (Tanganyika's). I have a 40G tank and lately I have been doing about 10-15 gallon water changes every other day. The Amonia still has not gone down. I also use API amonia bloc every other day to keep the amonia non toxic. Also, in the past week, my water has been getting extremely cloudy and the top has a cloudy/milky looking layer. I am using two bubble airstones, I have a fluval 204 filter, and I currently have fake plants and a fake rock cave. I am only feeding them twice a day and the past few days I started feeding them once a day because of the amonia. Please inform me of what is going on? My fish look entirely healthy and they are always active and hungry. I just want to find out asap so I do not lose my fish. Sorry for the long description I just wanted to give you all of the information on my tank's setup. Thanks.