I suggest you take those damsels back. They are aggressive and will give ur new fishes problems unless ur new additions are gonna be aggressive too. Up to you
About the tank, do u have a heater? You should get another powerhead too because two PH's make better water movement for the inhabitants than just one. Also you should add more LR
, about 35 - 40 pounds of LR
is good for ur tank. LR
will help filter ur tank so u can return ur canister filter if u want. Or you could trade that filter back for a small skimmer. I don't know if i should suggest u a skilzter as it is cheap (i have one) but its performance is "not good" if u dont do some modifications to it.
Add more LR
, wait for a few days (i can believe im telling someone to wait 0.o hehe). Test the water. If all paras are good, ur set i guess