Help advice

Hay man I have to jump in on this I know a guy that had his tank crash even killed his fish he tried putting more fish in and bam they died too he was not cleaning his gravel and after a year it started killing every thing. GH grow over every thing this is when he started to listen to me and I helped him clean up his tank and now there's no algae growing gave him a hydro Korella 3 for flow he bought a HOB skimmer and is using that now. The only things that survived his crash was GSP and devils hand frag I gave him tough stuff those two corals are. I have a couple corals waiting for him.

Bill