kona reefer

It doesnt look bad from this picture You made it sound like a frog pond in july. A few emerald crab will help with the bubble algae. You could try some carbon dosing. Getting your ph and alk up alittle more might help too. Tank looks nice throw up a few pic of the skimmer and how its plumbed up Maybe we can diagnose the problem with it

Nice set up and welcome to RA

Thank you for the compliments. However, that picture is from May of this year, and I wish my tank still looked like that. Trust me, it is quite a bit greener that; I just couldn't put up a recent tank picture as it is embarrassing.

On a side note, looking back I realize the large colt coral in the upper right of the tank has shrunk to about 50% of its original size. I bought it as a large adult colony in April from Premium Aquatics and was completely happy for a month. Then all of a sudden it shrunk and looked like it was going to die most of the summer. However, it has firmly attached to the rock and has been opening up for the past month. Still, it has never looked as good as it did during the first month. I wonder what is going on? All my other soft corals have grown quite a bit and have never skipped a beat.

The colt is a hardy coral but needs clean water, strong flow, and good lighting. I had a huge colony in my 29g under PC lighting for several years. Leathers don't like aluminum in the water, like some nitrate extractors use. Also, watch your fish from across the room to make sure none are nipping that coral.

Any chance your tank temperature is getting higher during the daytime, more than what you posted?

No aluminum media used, only GFO. Temperatures recently started getting closer to 82, but I have knocked it down to 76 again (the basement was collecting a lot of hot air, opened up some windows in the house to get some airflow). However, I'm pretty sure the coral was retracted before the temps started warming up for the summer.

Just for the heck of it, double check your thermometer against another one.

Does the Colt coral brush up against any other neighboring corals that may be stinging it? I would do a few water changes to help perk it (and the other livestock) up.