Is a 1" bulkhead enough to supply an 1100 gph pump?

[HippieSmell]

I want to drill my sump for an 1100 gph return pump, but I'm afraid to drill a hole large enough for an 1 1/2" bulhead in a 29 gal tank. So, I was wondering if a 1" bulkhead would supply enough water for the pump.

 

[WarDaddy]

1" overflow? or a 1" closed loop, where the pump is actually pulling through the 1" hole?

Either way, I think you need 1 1/2 but a closed loop 1" would be less of a problem than a 1" overflow. Gravity through 1" I do not think will keep up with an 1100gph pump.

 

[HippieSmell]

Not a 1" overflow (the overflow will be larger). I mean a 1" pvc pipe from the sump feeding an external return pump to the display. So you don't think 1" will be enough? Won't a 3" hole for a bulkhead to fit 1.5" pvc be too big? I'm just worried about the tank cracking.

 

[WarDaddy]

I pushed 1100 through 1" for a while, but was having micro bubble problems. It can be done. If you are bringing the water up from the sump, why not just take th pipe up outside the tank and come over the rim with the returns?

 

[jdieck]

There is high probability that with 1" pipe for the pump inlet the pump will cavitate. 11/2" will be my recomendation regardless of the diameter of the connection at the pump's inlet. A 11/2" Bulkhead will require a hole with a diameter from 2 3/8" to 2 1/2"

 

[HippieSmell]

<a href=showthread.php?s=&postid=6562664#post6562664 target=_blank>Originally posted</a> by WarDaddy
If you are bringing the water up from the sump, why not just take th pipe up outside the tank and come over the rim with the returns?

That was my other idea, besides using a submersible pump. Is there increased head pressure by going over the top? Or any other disadvantage?

<a href=showthread.php?s=&postid=6562725#post6562725 target=_blank>Originally posted</a> by jdieck
There is high probability that with 1" pipe for the pump inlet the pump will cavitate. 11/2" will be my recomendation regardless of the diameter of the connection at the pump's inlet. A 11/2" Bulkhead will require a hole with a diameter from 2 3/8" to 2 1/2"

The bulkhead I'd be using is from savko, and it requires 2 5/8" hole I guess, not quite 3" like I said. Is that hole too big to be safely drilled IYO?

 

[jdieck]

First I want to clarify. The 11/2" diameter I am talking about is from the sump to the pump. From the pump to the display tank you can use 1" if you do not have many fittings and elbows and you are using a pressure rated pump. If your pump is powerhead (open impeller style) like a Mag Drive then 11/4" is as low I would go from the pump to the display as their flow is rated assuming 11/2" discharge pipe diameter.
Going over the side or trough the overflow will be the same head pressure as you need to go to the water surface either way assuming you need the same number of fitting to rout either alternative.
If your sump is acrylic, a 2-5/8" dia hole will not be a problem, if it is glass the higher the diameter the higher the risk of braking it.

 

[HippieSmell]

I understood what you were saying, my worry is drilling a huge hole in my glass sump. I think I'll just go over the top (of the sump) to the return or use a submersible. I wish I had an acrylic sump, then I wouldn't worry at all.

 

[jdieck]

<a href=showthread.php?s=&postid=6563346#post6563346 target=_blank>Originally posted</a> by HippieSmell
I understood what you were saying, my worry is drilling a huge hole in my glass sump. I think I'll just go over the top (of the sump) to the return or use a submersible. I wish I had an acrylic sump, then I wouldn't worry at all.

Over the top to the pump is not recomended. All centrifugal pumps require positive suction pressure. This kind of arrangment will lower the pump capacity and will not be self priming increasing the chances of running it dry . Your best alternative for not drilling will be a Mag drive 36 (24 minimum) submersible. which at 8 to 10 ft head (Include elbows valves and fittings) with 11/4" dia pipe will give you about 1200 to 1300 gph

 

[Entropy]

IMO you don't want to restrict the intake of the pump with a 1 inch bulkhead, so go for the 1.5 inch. To be honest I would replace your sump with acrylic, before spending money on a new pump (unless you don't have a pump yet). It would probably end up being cheaper. You can pick up a used acrylic tank for pretty cheap in most cases, especially since you can used scratched, or ugly.

 

[HippieSmell]

Gah. As hard as I try to save money in this hobby, I know that cutting corners is more expensive in the long run. So, I'll take everyones advice and get an acrylic sump from glasscages, since they'll be in town next month, and drill everything for 1.5" bulkheads. Thanks people.

 

[Entropy]

I think that is the best idea. Acrylic sumps are much more versitle and easier to play with. Glass for tanks, acrylic for sumps!