Help with waterflow

Nardi · Dec 7, 2023

I have a 35g cube and am struggling to find a spot for the pump. My blood shrimp molted a couple days ago and there's still fragments in what seems to be a dead spot in my tank. It's a 20x20x20in. Should I get multiple powerheads? I have a hob skimmer and filter on the back and just the one 500gph circulatory pump on the front corner. Just worried to much flow will upset the corals. The light just turned on in this picture so they are looking a little rough.

Any help or advice would be greatly appreciated.

Nardi · Dec 7, 2023

The dead spot is in the small opening at the bottom center.

Mr. Mojo Rising · Dec 7, 2023

IMO a tank should not rely on a return pump for flow, it should have powerheads. IMO flow is very important and often underestimated, we are replicating the ocean after all.

Two powerheads are always better than one because then you can point them at each other so the flow bounces and creates random patters.

With that said, its not easy to position powerheads to eliminate dead spots, and its something that you will change over and over again through the years, as you add corals and they grow. One trick is to put an airstone into the tank when positioning powerheads, the bubbles will show you how the flow is.

Nardi · Dec 7, 2023

Mr. Mojo Rising said:
IMO a tank should not rely on a return pump for flow, it should have powerheads. IMO flow is very important and often underestimated, we are replicating the ocean after all.

Two powerheads are always better than one because then you can point them at each other so the flow bounces and creates random patters.

With that said, its not easy to position powerheads to eliminate dead spots, and its something that you will change over and over again through the years, as you add corals and they grow. One trick is to put an airstone into the tank when positioning powerheads, the bubbles will show you how the flow is.

Thanks. I do have another 480gph pump I can put in there, just seemed like a lot of flow for a small area.

Do you have a recommendation of placement for them?

Mr. Mojo Rising · Dec 7, 2023

Nardi said:
Thanks. I do have another 480gph pump I can put in there, just seemed like a lot of flow for a small area.

Do you have a recommendation of placement for them?

I had 2 gyres in my 32 until I upgraded to my 40, now I have 2 gyres in a 40. A lot of flow is a good thing.

As mentioned, best to position them so they somewhat face each other so the flow can bounce off each other to create random flow patters. You can also bounce the flow off the glass. Basically you just want to avoid a one way linear flow.

I always suggest to have one pointed at the water surface for agitation and help oxygenate the water.

Nardi · Dec 7, 2023

Mr. Mojo Rising said:
I had 2 gyres in my 32 until I upgraded to my 40, now I have 2 gyres in a 40. A lot of flow is a good thing.

As mentioned, best to position them so they somewhat face each other so the flow can bounce off each other to create random flow patters. You can also bounce the flow off the glass. Basically you just want to avoid a one way linear flow.

I always suggest to have one pointed at the water surface for agitation and help oxygenate the water.

Gotcha! Looks like I'll probably end up upgrading to a couple powerheads that can sync up and work together as opposed to the ones I have now that are just toggle on and off.