Thank you guys for advice. I would agree about too much phosphate because it is very small skimmer-less tank and I will try to keep it as long as possible. Eventually I will upgrade to bigger one, but I want to make sure I understand everything before spending lots of $$$ for bigger tank.
SO it is 3rd day for my clown fish and Yellowtail. Clown fish is chasing around by the glass and I think he is not accommodated yet, at least he doesn't eat yet which is my concern. What if he doesn't eat for next couple of days - can he die? Yellow tail looks like is very fine, started to eat but I didn't notice any aggression. They both swim together sometimes. Another thing I've noticed they don't hide in rocks. Clown is in the top of the tank swimming by the glass, but damsel is in the middle of the tank. Is it a normal behavior? Thank you for lots of help.
The worst case scenario it will be just damsel tank
but I love the clown and would love to have a pair and a coral to host them (not sure I can have any in 7g tank
)