seahorse scratching


Love my tanks!
ok so I got my babies and they are eating and swimming about. they do on occasion scratch themselves with their tails... also a little on the macroalgae I have in the tank. there does not appear to be any visible issues with their skin. I have had a diatom bloom recently and sometimes it appears they might have a little on them trying to shuck it off but I wanted to get some opinion on this.
I would increase your flow if they have diatoms growing on them. Also I wouldnt be surprised if they have some sort of issue going on, from the pictures you posted their gill looked really red. Not much you can do but feed them and hope they bead whatever it is on their own, unless you want to pull them and try QTing and treating.
What are your water parameters like? Scratching is often a sign of water quality issues. If that's not it, then it's quite possibly parasites. Check the water quality first, and report back the specific values. I.E. temp, salinity, ammonia, nitrite, nitrate, ph, alkalinity.

If that isn't it, I can start talking about different things to look for and treatment options for parasites.