Powerhead Set up

[CrabLegs]

I have a 75 gallon half circle that has been running for about 9 months. Right now I only have a Rio 2500 for the return, no skimmer (I know I need 1) about 25 lbs. of live rock ( I know I need more) Bio Balls in the wet/dry filter. The overflow is in the middle and I have the return on the right side of it kind of pointed to the left front middle of the tank agitating the surface.

I have a bad case of Cyanobacteria I think, (pictures online look the same) soft dark purple stuff covering my sand bed.

I just ordered 2 Koralia Evolution 1150's and was wanting advice as how to place them in the tank. One on each side aimed at each other?, Aim them to the curved font of the tank?, One high and One low on opposites sides? Both on the same side?, Etc.

Also should I rinse all the Bio Balls in old tank water or do half one week then the other half?, Take the bio balls out completely? Right now it is fish only but will want coral etc when I get a good light.

 

[huma-huma]

Powerhead placement is a case by case deal. What will work for one person may not work for another. Id start off by placing one on each side of the tank. Let them run for a week or so and see what happens. Ive noticed in my tank that algae starts to form in lowflow areas, so i simply readjust the powerheads a bit and wait to see if it solves the provlem. As for the bioballs, i would look at ditching them for live rock rubble or macroalgae

 

[CrabLegs]

Thanks for the reply, one on each side against the back wall pointing at each other? This tank being a half round I'm confused how to aim them.

Also if I take the bio balls out should I take them out all at once or a little at a time? I thought there was good bacteria in there to help? I am lacking on the live rock right now, I need about 50 lbs more. I set this up not realizing every thing costs a lot to get going, so I am adding things as I can afford them.

 

[huma-huma]

I would remove the bioballs gradually over time, but you will need to replace it with live rock. (you can use base rock but you would have stretch out the replacement time considerably) there is beneficial bacteria on the bioballs, however they only help to convert ammonia to nitrites, then to nitrates... They do nothing to help remove nitrates (which is what live rock and macro help do) this is why people running bioballs commonly experience nitrate issues. Put one on each side of the back wall, up towards the top, and aim them downwards into the middle front of the tank