New here, flow rate question.

Hello all,

I am new here at thereeftank. I was recently bit by the SW bug so I've been giving the subject all the attention my freshwater planted tank allows over the past 2 months. I feel that I have the basics figured out. I'd like to give you all an outline of my tank thus far then ask a question I can't figure out on my own...

The tank, an Aqueon 15g tall/column, 7 weeks old. For equipment I'm running a AquaC remora S skimmer and two hydor koralia nano 240 power heads. Lighting is a retrofit RapidLED fixture (3 neutral white, 4 royal blue , 2 420mn violet) ..The tank was started with live sand and 15+/- LBS of uncured live rock..I introduced a CUC two weeks ago ( a few hermits, few nerites and one turbo snail. I let it run its course while sucking out die off and doing water changes. . A Solid cycle took place. Just today I added an ocellaris clown pair
Ammonia 0 (over 3 weeks)
Nitrite 0 (over 3 weeks)
Nitrate around 5mg/L

Sorry for the long list of information. From what I've noticed most members ask for a basic description of the OP's tank.

My question... My two clownfish seem to be swimming around quite a lot even once the lights turned off. I'm trying to decide if two koralia nano 240's and a Remora S (run by a maxi1200) is to much flow. I have both power heads mounted on the back of the tank.. One on the bottom left and one on the upper right. Total flow is about 770gph. I feel its a lot for a 15g tank. For tonight I unplugged one of the koralias. I'm looking for recommendations for flow amount or best placement of the my current equipment.

Thanks a lot!