Importance of surface agitation

[clancaster23]

I have what's basically a coast to coast overflow box on the back of the tank that sends water down to the sump. I know most of the time you want surface agitation so you can get the whole gas exchange thing going but considering how much water I have being moved from the tank through the overflow down to the sump, do I need a wavemaker hitting the surface? I have one Jebao WP40 in it now and won't be able to get another for a month or so but I'd like to direct the pump down into the tank or maybe just lower it to get a better current to some of the corals until I get a second wavemaker.

 

[Aquarian]

What's your turnover rate? You should be fine without surface agitation if your turning over enough water.

 

[mariobrothersleeve]

I would recommend keeping the surface agitation. With out that you will have white bacteria blooms on the surface and horrible co2 in your tank limiting dissolved oxygen. Your corals will suffer more from the pH swing vs. Flow.

 

[Aquarian]

I was thinking about that too but with a coast to coast pulling the entire surface to the sump with enough flow wouldn't it get enough oxygen?

 

[mariobrothersleeve]

I was thinking about that too but with a coast to coast pulling the entire surface to the sump with enough flow wouldn't it get enough oxygen?

All depends? If stand pipe is full siphon, I would say no? There would be no break at the surface causing the water tension even with the c2c pulling down. Can you angle the return?

 

[Aquarian]

Ah yes that's a good point

 

[clancaster23]

Can't really say what the exact turnover rate is. It's a 180 gallon with a 40 gallon sump. I have a 1500 gph return pump running at full speed pushing water through the system. The overflow sticks out from the back about 5 inches just about all the way across the tank and about 10 inches deep. I figure it holds about 8 gallons of water in it as it flows into the overflow pipes down to the sump.

 

[clancaster23]

It's a dual durso downflow setup. Not sure what you mean by angle the return.

 

[mariobrothersleeve]

The return to tank. Is that a poly - lock? Can you flex it towards the surface? 1 WP40 for a 180g is very low cycle rate. Your co2 saturation is probably very high to begin with, I wouldn't turn the power heads down. Just try to keep the fish alive for now?

 

[clancaster23]

No, all the return plumbing is solid pvc. I have it plumbed to go over the rim of the tank and it goes down into the water about 4 inches then I have an 90 degree elbow so it isn't going straight down and blowing the sand all over. The one WP40 has done fine for these five months I've had it running although I know I need another one and plan to get one soon but both my fish, a chromis and blonde naso, are doing just fine.