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[andyt_uk]

not exactly new to the hobby.. but my tank has been dry for 12 months and have just recently setup again.
have added 20kg black gravel substrate to replace the white sand i used to have, filled with water, added conditioner, started filter, turned on heat
i added some methylene blue as the tank had crashed previously killing all stock (thats why i sulked and it stayed dry for 12months) everything was cleaned but wanted to be sure..
then a couple of days later the water started to cloud.. i havent fed it so doubt its a bacteria bloom, ammonia, nitrate and nitrite all at zero, pH 6.8 to 7
temp about 84F
i added some filter aid and in 3 or 4 hours the water was almost clear..
12 hours later it was starting to cloud again till 24 hrs after the filter aid was added i can barely see a few inches into the water

so what is it? do i add more filter aid till it stops coming back? do i drain and refill?

thoughts and ideas gratefully received

 

[Curiosity101]

Long shot here, but are the filter pads the ones used 12 months ago? Could it be there was some dry mulm and leaf matter/food etc on them? Perhaps since it's been put back it water it could have begun decomposing. But no where near enough to actually show any ammonia?

Like I said...long shot...

 

[andyt_uk]

its a canister filter with several different media in there, it is the original stuff and i did figure if there was any organic matter in there it would actually be useful..
i'll keep testing water, i have added more filter aid to see if it clears again