Cloudy biorb aquarium

Question
My son has a baby biorb aquarium with two goldfish in it. We have had it
trouble free for 5 months. Last week he did a 75% water change and
replaced filter with new 'service kit'. He also agitated the rocks at the bottom
to give a good clearout, the first time we have done this bit. 24 hrs later the
tank is as cloudy as a dense fog. The ammonia and nitrate levels were really
high despite putting in ammo lok and stress zyme. For the past 3 days we
have done a 50% water change adding stress coat and stress zyme each
time. The tank is no better at all. Amazingly the fish seem ok!! How can we
get our tank back to normal. There seems to be no improvement at all.
Thanks.

Answer
Helen,
the water change disrupted the bio cycle of the tank, and the large water changes are doing the same thing.
first off, cut the water changes to 10% you can do this daily untill the levels fall off.
ammo lock will only take a finite amount of ammonia out and then will dump it back in if it is not removed.
stress zyme is safe and will not cause you any trouble.
watch the feeding, don;t overfeed, and remove any uneaten food after a few minutes, like 10 or so.
also if you have plants, any dead or dying plants have to go as well.
this will eliminate the raw material that is causeing the bacteria bloom which is what that cloud is.
when cleaning the gravel just do the top 1/2 to 1 inch and leave the rest its a bio bed in progress and you don;t want to disturb it if possible.
I think you will be fine and enjoy your aquarium.