You need to test your water for phosphates, nitrates is the big one here. NEVER add anything to the tank without testing for it first. If you don't know what is in the 2 bottles your talking about then don't add them.
Your lighting is WAY, way too low for anemones, take them back asap or get some better lighting. They will live a short time before they die and fowl the tank even more.
Way too many critters in a 20.
sounds like they are selling you things you don't need, anemones need very good lighting(which you don't have) and feeding once in a while. Feeding some shrimp, krill, silver sides is what it needs.
If you have better lighting 1 anemone is all you should have and a few fish to go with it.
Please read, read and read more and aske questions before you waste your money listening to the LFS
. There after your $$$ were not..
Did I say... take the anemones back ASAP!!!