Waterpump questions

[Jimothy]

I am trying to select a waterpump, the Mag Drive seems to be the brand I want though I have no idea how powerful a pump to buy.

My return will be vertical, and I have read about head loss and pipe length, though the return system I am building will have 4 or more holes set in different directions on a vertical column, and a 1/8" plastic tube just below the surface to break a reverse-flow siphon when the power goes out.

Should I go with the MagDrive 24 and use a ball-valve to reduce the flow, or is that far too powerful for a partiallyfull 180g tank and 65g sump?

 

[jsoong]

You don't want to use a ball valve on a return pump - it burns out your motor to have it work against the resistance. Better option is to put a T in the return line, one arm of the T goes to your display, and the other returns to your sump. You put your ball valve in the "sump" arm to control how much water is diverted back to your sump (thus controlling the flow into your display.)

This is the flow vs head height table for the Mag drive:
Head Feet 0 2 4 6 8 10 Max ht Watts
Mag Drive #2 Flow (gph) 250 7' 24
Mag Drive #3 Flow (gph) 350 325 270 177 77 20 10.5' 35
Mag Drive #5 Flow (gph) 500 410 310 180 75 10 10.5' 45
Mag Drive #7 Flow (gph) 700 550 480 400 300 120 12.5' 60
Mag Drive #9.5 Flow (gph) 950 900 800 720 600 400 15' 93
Mag Drive #12 Flow (gph) 1200 1150 1100 910 700 600 15' 110
Mag Drive #18 Flow (gph) 1800 1610 1350 1100 1000 900 22' 145
Mag Drive #24 Flow (gph) 2400 2200 1900 1700 1500 22' 265

You can size the pump based on your desired flow rate.

 

[jsoong]

Aargh! The stupid computer won't let me format the table in nice columns!

Here's the link to the original table (it is at the very bottom of the page):

Aquarium pumps, pond Pumps,Rio, Reeflo, Sequence, Eugene Danner, Supreme mag drive, Little Giant

 

[jsoong]

An answer to your other post re: canister:

On the picture, it looks like you have both the return & output of the canister in the display. If that is the case, you don't have to worry about back siphon. The canister is sealed, so even if there is a power failure, there is nowhere for the water to go. So you can keep the intake deeper in the tank (below the water line when the main return pump is off) to prevent it sucking in air on power up.

<If you have the intake in the sump & the return in the display, then you would indeed have a back siphon problem. However, this is a poor placement choice as canister filters do not have powerful enough pump to drive water up a few feet of head height.... I tried that & my Magnum 350 is down to a trickle at 4' of height.>

 

[Jimothy]

Thx for the info, I went with #24, my return will have little head loss due to pipe length, though inside of the display I plan on using T's facing different directions to ensure flow to odd places like the underside of the ramp.

re:canister filter:
The picture is what I wanted to do with the filter, but I was unable to find a split pipe, I only have one hole to use and have seen too many youtube botched drillings to try and drill a second.
The canister is not drawing from sump and emptying in display, it is drawing from display and emtying in sump. I can break the siphon with a small hole, but can only hope that water fills display fast enough to prevent too much air from getting to canister.
I assemble plumbing tomorrow, will post photos, though I'd appreciate more design feedback. Thanks.

 

[jsoong]

If you are drawing from the display with the canister, I would suggest putting the canister filter lower than your sump water line. At this position, the canister will back siphon until the intake sucks air. However, the water level in the canister will not go lower than your sump water level. Since your canister is below the sump, it will not empty. There will be air in the pipes, but the canister itself will still be primed & ready to go on power up.

BTW, you don't have to use the drilled hole for the canister. You can hang the canister in/out over the tank (I know that might look ugly!), thus giving you a free port for an extra standpipe & what not. <Reason you might want an extra stanpipe is that at 2000 gph, one drain might not be able to handle all that flow. Most people have 2 stand pipes for flows over 1000 .... plus it is insurance if one gets plugged.>

 

[Jimothy]

I would need to go through a metal hinged screen to use the Fluval405 over-the-top, and I dont want to. Also I would have to get new hoses for a longer reach, so I am going to filter the sump and forget about drawing from the display tank.


Here is a pic of the basics of my tank, holes that are drilled and glass overflow... how would you set it up?

 

[jsoong]

I think that the canister would filter just as well completely from the sump.

If don't know anything about turtles & their water flow requirements. But if I were to plumb that tank for fish, I'd have 2 stand pipes at the 2" holes & have the return pump coming through the 1" hole.

With 2 standpipes, you can also play with some of the other designs for silencing the flow. Eg. you can have a completely submerged siphon standpipe inside the overflow box, and have an open channeled emergency standpipe overflow in the other 2" hole. This design is said to be totally silent (better than the Durso & less fiddly), although I have not tried it yet. <I will be doing that soon - I have a second hole in my overflow box....>

This is the basic article on the overflow:
BeanAnimal's Bar and Grill - Silent and Fail-Safe Overflow System
This has a 3 standpipe design, although on the original post <this is a modification of a design in a reef forum>, the design only called for 2 standpipes as the open channeled standpipe also acts as the emergency.

One drawback with my setup is that the standpipes are only drawing water from the top of the water. You might have problems with stuff accumulating in the bottom of the tank. This may be decreased with having your return water pointed to the bottom & keeping waste suspended so it can be picked up by the overflow. Others have to resort to small power heads inside the tank to eliminate dead spots.

 

[Jimothy]

My MagDrive 24 is still in the mail, along with strainers and ball valves needed to complete construction, though I have finished the in-tank part of the return line and completed design.
I will start a new thread in DIY now that design is enhanced.