Grouper rubbing on sand

[Guynamedfish]

My grouper has been rubbing himself on the sand and he has been eating quite well also he has this mark I thought at first was just his coloring it’s not identical to the other side hes hard to tell I was thinking the temperature because I have a glass lid heat gets trapped so it gets hot like today it was at 83 is that why the grouper is rubbing himself on the sand or no if so how do I cool down the tank also the grouper is a dark hind grouper

 

[Fudsey]

You should remove the glass lid and have a fan blow across the top of the water to cool the water. You could also put some ice in zip lock bags and float them but this can cool the water too fast in the area of the bags.

As for the mark, It's hard to tell exactly what it might be. Could be a wound from something and he's itching it on the sand.

 

[JumboShrimp]

My 150 gallon FOWLR tanks (with glass lids) run 84-85 degrees all summer long, and I have never associated it with flashing. So that’s my 2-cents. I would look for another cause.
:(

 

[Guynamedfish]

Ok any ideas because it seems like he’s doing it more and more frequently he also has to hide above the live rock like hiding on or In between equipment like it shows I. The picture

 

[Guynamedfish]

How can I help him

 

[JumboShrimp]

I would start with the full course of treatment of API General Cure, in the event of gill or skin flukes (difficult to see without magnification). Even local pet chain-stores sell it. (And of course Amazon.) Add 1 packet per 10 gallons, etc., etc., per the directions; directions can be found online. But ADD to your aeration, as in double it. Lost of good info here at R2R on the product if you do a "Search." Keep us posted!

 

[Guynamedfish]

I think I have that will that effect my invertebrates though I have 1 chocolate chip starfish