Recently (past month)my F8 puffer has started to loose its black color on its back but this week it seems to be just hanging around and not to energetic even when I feed him. The GSP that is in the same tank has not changed color or the way it acts. 

Information that can be helpful: 

Attached is the water test that I just did.

I just checked the salinity and it is at a 1.015 it’s always been kept at a higher salinity than I was told to use. LFS said 1.008. But they have always been active and seemed to do better with a higher salinity. Some people on here recommend full salt.

In January I got a whole new set up and let it cycle for approximately 6 weeks. I used 1/2 new water and then water from the old tank to help it cycle but no fish were added until it was all running and cycled. I use the live sand that I’ve always had in my tank.

Food is a mix of blood worms, mysis shrimp, frozen krill, cooked shrimp from the supermarket, and snails

F8 I’ve had for approximately 9 months GSP is about 16 months 

Water changes is 10 gallons of Poland spring mixed with salt before adding to the tank 

The new tank has more drift wood than the previous tank. I was told this lowers the PH and the LFS gave me a ph booster however it looks to be ok without the booster. I know F8 do better in 7.5-8ph water. 

Temp is 78 degrees at the main heater and I have a smaller heater to keep the other tank at the same temp. 

 I got a new Aquasky light that’s on for 10 hours a day 1 hour for sunrise 8 for day light 1 hour for sunset. Then it goes to the blue moon light for about 8 hours and then fully off for 6 hours 

The only thing that I can think of is because it’s spring where I live. The tank is near a window and the suns out a lot more that it is was. The tank gets more light and is brighter that during the winter. The F8staying closer to the bottom and getting a lighter color for camouflage. 

Help with color loss