I have had my 50g tall tank cycling for 8 months i recently purchased a frogspawn and flower pot coral they were doing awesome for about 4 days now dont want to open what could cause this
I'm not familiar with the flower pot coral, but as for the hammer, I know that they don't like a whole lot of flow. Just enough to make them wave at you. That might be one thing to look at. Another thing might be to move them lower in the tank and slowly move them higher to acclimate them to your light. It's possible they would have been doing okay for the first couple days until the zooxanthellae began to over run the coral tissue causing them to close up to reduce photosynthesis.
+1 to the above posts. Both will close up with too much flow.
Also the flower pots I've had don't like a lot of light so try moving it to the bottom. Flower pot corals are some of the most difficult to keep alive long term.
Also, welcome to the site, and remember, to take it slow and steady. I like to research all my buys before hand and try to poke holes in my plan for their survival in my tank.
There's not a lot on corraline or alge or detritus in there for being up for 8 months.
You'll want a bacteria like dr Tims one and only and feed the tank. Check your nitrates (no3 ) and phosphates (po4). Don't drain your frozen foods use the wet stuff too. It feeds the bacteria you want on the corals and provide dissolved organics to both corals. You may need to spot feed both of them.
You probably want both of those on the sand to acclimate to your lights. It'll also help if the rock is new and is still buffering the ph. The sand is cured better than the rock.