Real FF you need to do more research. Forums are great for specific questions, but you need to read every article you can about how to cycle, stock, and maintain a SW
Your light will be fine for a FOWLR
, having a skimmer on a 20g is good, and you have a ton of LR
. These are good things to start with, and you are on the right track. Look into powerheads, you will want 10-20 times your tank's volume in flow (20g tank=200-400gph flow rate). The ocean is very turbulent and the flow simulates your inhabitants' natural environment.
At this point I would leave the clown(s), but take the anemone back to the LFS
and if you still have that Tang, take it back too. Tangs need much more space than your aquarium has.
We've all made mistakes and wanted things that we aren't capable of caring for properly. I am guilty of this (orangespot filefish, flame angel both deceased
The important thing is to learn form our mistakes.
I have 2x 20g FOWLR
tanks, and there are many fish and inverts that are appropriate for this size tank. Just be sure to research animals before you buy them!
The red stuff on your rocks looks like coraline algae or possibly zoanthid corals.