How to determine return pump size?
 

I have a 58 gallon tank, aiming for about 250-300 GPH.
The distance from the pump to the outlet in the tank is about 5 feet.
Of course there will need to be either 90degree elbows, or 45's.
I know 90's cause A LOT of resistance.

I tried to google this but all I found was that using PVC piping is advised ?AGAINST? on the return line??

It causes less resistance to use flexible vinyl or silicone tubing?
Do most people use flexible vinyl tubing?

Appearance isn't really a big deal, the whole thing will be concealed.
So how do I determine the heading, and what material should I use??

bump

Oh I would highly recommend using flexible return line. Use as little hard pvc as possible. It's so much easier on your pumps w/ flexible line. And you don't have to worry about leaks with all the pvc joints.

I don't know why people use hard pvc.

so far flexible seems the way to go. even on the intake side too.

So how do I determine head height?
Could I just guess-timate?
about 5 " plus another foot or two for any bends.
I guess that would put me at about the Mag Drive 5.
Flow rate: 500 gph
max head: 10 ft.
I was planning 300gph+ so I guess that seems good, right?

Yea, generally you're looking at 3 or 4 feet to the tank. A Mag 5 would put you in the 310-380gph area.
With flexible line, you won't really have the bad bends that occur in hard pvc. I'd say a mag 5 would be fine for what you say you want. Put a ball valve on the return line to control flow. It won't hurt to dial it back slightly if you need.

All you need is 3-5x turnover through your sump. I would use an Eheim 1250. Should be very little head loss using spa-flex.

I was told that each 90 is equivalent to about 1 foot of head pressure. I agree that the use of as much flex tube as is "reasonable" is the best solution.


Dan

seems like flex is the way to go. which is the best to use?

flex pvc= flex pvc. There isn't one that is better than another.

Numerous locations online to order - here's one [url]http://www.flexpvc.com/[/url]

Some of big boy hardware box stores carry it.

I would also go with a eheim pump

I hae used Mag pumps but personally I will never have anotherone inside my house. They are just to noisy.....

Eheims are 2x's the price but they are silent!!!

I replaced my Mag pump three times so far in a year. IMO the Eheim pump is cheaper in the long run.

I like using vinyl tubing on smaller tank. It absorbs vibration a lot better than hard pvc.

so, do you think the eheim 1250 would be okay.
It says 320GPH 6.5 ft max head.
I'm having with the head loss calc. It seems just not right.
Or i'm not using it right which is more likely.
On the DRfostersmith site it says
outlet: 12/16 mm millimeters? geeze. What size tubing is that? 3/4inch?

Anywho should I use that pump or the next one up which the 1260.
Quite a price jump between the two from $70-120. woo.

Note: I'll plan to have power heads inside the tank, plus more than likely an Eheim 2217 canister pump which pushes about 250GPH I believe.