Power head question

[Pastor Salty]

I have a 75 gal tank and was wondering how many powerheads do you think it will take for proper flow? Right now I have only 1 powerhead set up on the right upper corner of the tank. Do you think it would be smart of me to place a smaller PH on the other side maybe in the middle of the tank for more flow or leave it alone?

 

[Smitty]

Welcome to site....you'll definitely need more flow in there. The rule of thumb is to have at least 10x your tank volume. So the size of the next powerhead depends on what powerhead you already have in your tank.

 

[little_fish]

Hello and Welcome!

Having lots of flow is important for the health of your fish and corals, it brings in oxygen and remove CO2 from the water, keep stuff from settling out and prevent algae issues.

I personally like 20-30x tank turnover per hour

 

[marcah]

depending on what you are going to want for corals down the road SPS require around 40 times your tank size per hour for movement so it really depends on what you are looking for for corals... softies around 20 and LPS 20 to 30 or so.... Before you buy a second powerhead decide on what you would want for corals down the road so you dont have to replace them again.. I would run two to three PH in it..

and howdy and welcome to the site...:D

 

[Pastor Salty]

Thank for the welcome and the info

 

[AmberSunrise]

Welcome. I have to say it depends on the fish you want some like high flow while others do not. I would definitely get one for the other side to prevent any dead spots which will cause algae and nitrates to build up.

Do you know what the rate of the one you have is?

 

[kbuser92]

I would run 2-3 of them, if not 4. It all depends on placement and output, along with your stocking. Fish only should be 10-20x tank volume, softies ~20x, LPS ~20-30x, SPS ~40x.

 

[active]

does the return from sump gph factor into part of the turn over -
say you want 30 times and have a 90 gal tank you want 2700 per hour movement
so would it be 2 ) 1000gph power heads and the 700 or 800 from the return or just like 3 power heads and the return plays no factor - just curious

 

[little_fish]

yes the return pump plays a factor, but due to head loss you dont get the same GPH as the pump is rated for

 

[Spaz059]

I'm trying to understand this a little better myself, so is the 40x or which ever you are using in your tank, is that a constant flow or a total flow?

Example would be if you have a wave maker that alternates your PHs would you take your combined flow of the PHs and return or the flow of what is running at one given time?

 

[kbuser92]

At one time, I think if I understand. At any given moment, if you were to add up everything that was running, thats your turnover. But, and I may be wrong, I think running a wave maker is a little different, im just not sure how. Too fancy for me.

 

[active]

something like this - if you have a 100 gal tank and want it to circulate 40 times per hour you need 4000 gph flowing - so lets say your pump is a 1000 gph pump subtract the head pressure you have 800 gph - you still need 3200 more gph of flow - add the power heads to make up what you need to be close in this case 4 800 gph heads would work - or any combination for that matter - at least this is my understanding of it- if wrong someone please correct me

 

[kbuser92]

Thats right. But your skimmer also counts as long as its pump driven (i.e. not air) and UV sterilizers, etc...anything that runs with a pump pushing water in the display tank. The scenario above wouldnt have a HOB skimmer or sterilizer, but for one without a sump, they count.

 

[little_fish]

You dont count skimmers or UV in the flow.

And its total flow, if you have a wavemaker, you can alternate between all the flow at once or lighter

 

[Nonfamous]

So my that formula I would need 3600 gph flow, right? I have 716 at the return, and two 750s in the tank. That's 2216 gph and my poor polyp colony looks like its just barely hanging on! Its not in direct flow either. I cant imagine adding another 1400 gph inside the tank! It would be like a hurricane in there!

So are my corals safe at 25x? Yes I did account for head pressure.

 

[little_fish]

Soft corals dont like as much flow, but if you get into SPS corals then you will need more flow

 

[OceanCrazy]

Hey guys i just wanted to know if my max-jet 400 is too strong for a 38 g tank cause i can see 2 anemones that look like they in the middle of a tornado.

 

[Bifferwine]

I don't think so. I had a MaxiJet 1200 on my 10 gallon. It was a lot of flow, but everything in the tank was still fine.

 

[OceanCrazy]

Ahh ok ty

 

[Nonfamous]

Still, if I were to get into hard corals and needed 40x turnover, how in the world would I keep from creating a sand storm? Just for laughs, after posting here, I added my other 750 gph mixing unit to the tank. Now, it didn't create a full blown storm, but there is visible sand suspended in the water column.

For reference, my power heads are located in the back corners, driving to the opposite corner and mid tank. The third I just added is centered stage right centered in the water column. My returns are center pointing up to ripple the waters surface.