Tropical fish tank

[stanbesida]

I have two fish tanks, one is a four foot and the other is 15 inches, I use the main tank for a selection of fish including silver sharks, angel fish, Kribs and mollies etc. The smaller tank was originally purchased as a breeding tank but I transferred the Guppies and Neon Tetras into it as they started to disappear. The tank will be 12 weeks old tomorrow and whereas I have been unable to get the ammonia level below point 50 even though I have done numerous water changes, changing about a quarter of a tank each time, it has always remained the same but the PH was 6.00 On Sunday I noticed the Neon Tetras were all swimming at the top of the water and the water had turned cloudy, it actually looks like the weather on a misty morning, where the mist is "Rollling" I transferred the Neons back into a couple of small breeding tanks in the main tank so as to keep them alive, when I checked the water, the ammonia was up to 8.00 so I did a 50% water change and added some Nutrafin "B clear" it claims to clear the milky clouds in 24-48 hours but I am curious as to whether this is in fact bacterial bloom or something else? I have a Fluval 2 filter but I am a bit worried about removing any more water at present since there are no fish in the tank and it won't get any more bacteria without them.I added "Ammo Lock" to the water to de-toxify it, as it is supposed to take the ammonia from toxic to none toxic, I had been adding ammonia remover up until then and it hasn't done any good. I have just checked the water prior to writing this and the P.H. is 6.00 and the ammonia is 8.00 and I still have 2 minutes left for the correct result, but it doesn't read any higher than 8.00 on the chart, the Nitrite is NIL. Any suggestions will be greatly appreciated