return line size and reason

[1reepher-zn]

goodday fellow reefers

i have a new +- 1000lt / 300gal setup im trying to start my plumbing soon my question is what size should my return lines be iwas thinking of 32mm or 1-1/4" but ive seen some people use 22mm or 0.8inchs not sure what size to use i want to run 2 return pumps

thanks any advice will be welcome

 

[WVNed]

It all has to work together. How big is your overflow? How big are your pump outlets?
You size stuff to create a desired GPH turnover.
4 x 1 inch
2 x 11/4
How are you getting them into the tank? Bulkheads or over the top.
I would forget the 22mm ones. I made that mistake and had to fix it with 2 additional over the top returns.

 

[1reepher-zn]

It all has to work together. How big is your overflow? How big are your pump outlets?
You size stuff to create a desired GPH turnover.
4 x 1 inch
2 x 11/4
How are you getting them into the tank? Bulkheads or over the top.
I would forget the 22mm ones. I made that mistake and had to fix it with 2 additional over the top returns.

hi thanks for the the response they going over the top I'd like to use 2 return pumps for redundancy incase I lose 1 pump so will 32mm x 2 be ok

 

[WVNed]

I think so. Is 32mm a common size where you are? 1 1/4 is mostly for sink drains here and there aren't as many types of parts for it as for 1 inch and 1 1/2.

If you are doing over the top if you don't like it you can fix it later.

 

[WVNed]

You might read this
https://www.reef2reef.com/threads/300-gallon-moved-in.858975/

 

[1reepher-zn]

I think so. Is 32mm a common size where you are? 1 1/4 is mostly for sink drains here and there aren't as many types of parts for it as for 1 inch and 1 1/2.

If you are doing over the top if you don't like it you can fix it later.

I'm from south Africa

 

[1reepher-zn]

Was worried about if there will be back pressure if I go with smaller diameter pipe

 

[WVNed]

I have 2 pumps. I had to add an additional outlet to each return because of back pressure.
It's hard when you have never done a big tank before.

 

[nereefpat]

Was worried about if there will be back pressure if I go with smaller diameter pipe

Yes. Smaller diameter of the pipe win mean more total dynamic head, which will decrease the flow rate from the return pump.

I agree that I wouldn't go smaller than 1". Any idea what you want the flow rate to be? What about dimensions of the tank? 2 returns at 32mm is a reasonable start. You also might consider what the outlet on the return pump is.

 

[outhouse]

You want 1 pump and run 1" 1/4 ...... DC pumps flow better with larger diameter pipe. AC pumps do fine with 1" like Iwakis.

 

[outhouse]

also running 1 1/4 you will use less electricity as it flows better, im able to turn my DC basement pump down to 40% and run about 50W which is awesome for a basement pump. My 1 DC pump is rated to 18 ' of head pressure

 

[outhouse]

last note, just because you have a big tank does not mean you need a lot of flow. 500 to 700 gph is more then enough to run any sump on tanks up to 500G. I have 320 total G system and the above flow is more then enough. If you go any higher you will never have a quiet tank.

 

[1reepher-zn]

Ok thanks I'm planning on DC pumps the ones I'm looking at have a 32mm output

 

[WVNed]

I am running 2 8000L/hr pumps on my 240 gallon at 95% with about 2 feet of head.