urgent help needed

[coldwaterfan]

Yeah uk where everything is regulated by the gov.

I need to do a 50% change today and do the meds.

2 weeks ago new fish were added after what i though was the fault of the algea eaters my mrs got from pets at home.

 

[coldwaterfan]

I think i know what the issue is going to be. The tank has large and small gravel and the vacum i use doesnt cut it. Upon filling the tank up i used a hose turned on full and found the deeper sections of gravel to be full of fish poo. The tank has a 2000ltr hr external pump but its not helping remove.

Gonna have to go the home made vac pump route like i used to use as the commercial one is making it look like a section of tank is clear but its not.