GPH question

[Derbird]

Hello my fellow reefers.

I am in the process of upgrading my BioCube to a marineland rimless 60 gallon cube . It has the built in corner overflow. My question is how much flow can these tanks take? I have a friend who will make me a killer deal on a 900 GPH return pump but I'm not sure if this tank can handle that much

Any suggestions or input is appreciated

 

[user 26995]

It can depend on the size of the bulkhead in the overflow. And actually thinking about it, IMO 900 gph is going to be too big. I tried using a 900gph pump on my 75 and the return could not keep up. But what you can do is T off the return line so you can control the amount of water going back to the tank. run the T back into the sump. I have a 20 gal tall sump under my 75 and the 900 gph pump would empty my sump before it could be returned. I can check when I get home, but I am running either an eheim 1250 or 1260. I cant remember which. I am pretty sure its the 1260 which at 4' head loss is running approx 420 gph. that seems too fast. maybe I am running the 1250. that is only approx 198 gph at 4' head loss.

in any case, you can run the 900 and like I mentioned T it off so you can adjust the flow to the tank and run the rest back to the sump or refugium. You can also add to the line that is returned to the sump if you want to add any reactors to it.

 

[BEAU_RN]

All great recommendations especially having extra lines returning back to the sump for future upgrades with reactors and such.

 

[mfinn]

IMO a 900gph is too much for a 60.

I know lots of people use larger pumps than needed on their tanks and do the tee thing and use it to feed other devices, but I'm not a big fan of that.
I would look for another pump that would be more inline with what the job needs.
I would look for a pump that would give you about 300 gph in the tank.

 

[Derbird]

Well shoot, there goes that idea :doh:

So I need to think smaller. A mag5 would have about 254 GPH (RC head loss calculator) and a mag7 would do about 451 GPH, it looks like I should be looking in the middle of those two.

I think a mag7 or similar would be a good route to go. Any thoughts or suggestions

And a big thank you to everyone for the fast responses

 

[mfinn]

Well shoot, there goes that idea :doh:

So I need to think smaller. A mag5 would have about 254 GPH (RC head loss calculator) and a mag7 would do about 451 GPH, it looks like I should be looking in the middle of those two.

I think a mag7 or similar would be a good route to go. Any thoughts or suggestions

And a big thank you to everyone for the fast responses

I am in the slower flow ( through the sump ) camp so I would vote for the mag 5.
I know many here are the opposite and they would go with a mag 7.
IMO it's all just a personal preferance on how you want your system to work.

 

[Derbird]

I am in the slower flow ( through the sump ) camp so I would vote for the mag 5.
I know many here are the opposite and they would go with a mag 7.
IMO it's all just a personal preferance on how you want your system to work.

I like the lower power consumption that the mag5 would use, it is a significant difference. My only concern it if it would be enough to bring the detritus from the tank through the overflow. I will also be running a MP10 so this may not be a valid fear

 

[mfinn]

. My only concern it if it would be enough to bring the detritus from the tank through the overflow. I will also be running a MP10 so this may not be a valid fear

IMO that is what the powerheads are for. Or a closed loop pump.
I really don't like using the return pump for this.

 

[Mark2]

What's the diameter of your drain pipe and what gph is your skimmer pump in the sump?

 

[Derbird]

What's the diameter of your drain pipe and what gph is your skimmer pump in the sump?

It has a 1" durso drain. You know I have no idea what the skimmer is rated for . I'm going to use my old e-shoppes 150 to start with and upgrade later to a better quality skimmer. I did try to look up how many GPH the skimmer used but all I could find was the amount of air the sicce pump would draw.

 

[mfinn]

what gph is your skimmer pump in the sump?

what does that have to do with his return pump?

 

[Mark2]

Wouldn't you want the flow through the sump to be around if not faster than the rate of the skimmer to keep it running efficiently?

 

[Mark2]

That is, if it's too slow, the skimmer would be skimming already skimmed water.
If too fast, some water will be returned to the display unskimmed.

 

[mfinn]

It would be nice if you could process all the water going through your sump with a skimmer. But IMO it's not very practical.
My tank is a 240 gallon tank with a 85 gallon sump, and my skimmer feed pump is a maxi-jet 1200 which is about 295 gph.
That would create a stagnant water condition with little or no gas exchange.
I'd be growing mosquitos in my sump.