closed loop for my 240; will this work?

lagatbezan

lagatbezan

Member
Hi,
I'm in the process of setting up my 240g acrylic tank. Now this tank is a room divider which is visible from all sides. it has a center overflow build in it and i wanted to add a closed loop system for more water movement. I have drawn up a closed loop system to be placed on top of the tank where it will be hidden in the canopy on top of the tank.
Will this work?
What do i have to take into account and any suggestions as far as pvc tubing sizes and so on would be great. I'm looking at the quite one 4000 pump rated at 1017 gph w/ 1' in and out.
thanks.
hope image loads.
 
golfish

golfish

Active Member
it might work but its not going to be very efficient...The pumps not going to be very efficient having to pump water up, plus I wouldn't have it draw water from the overflow (not really a closed loop when you do that)
adding all that for just a 1000 gals on a 240 gal tank is kind of a waste. I'd just get a few large powerheads
 
lagatbezan

lagatbezan

Member
thanks for the reply golfish.
The pump would be pulling at most about 8 inches of water up. Is that too much for the pump to pull up? would i be better mayby trying to put the pum in the overflow box? the reason i didn't wan to do the powerheads was because i didn't want to have the wires and all showing in the tank.
any other suggestions?
thanks.
 
golfish

golfish

Active Member

Originally posted by lagatbezan
thanks for the reply golfish.
The pump would be pulling at most about 8 inches of water up. Is that too much for the pump to pull up? would i be better mayby trying to put the pum in the overflow box? the reason i didn't wan to do the powerheads was because i didn't want to have the wires and all showing in the tank.
any other suggestions?
thanks.
I think you'd be better off putting the pump below the top of the tank so it doesn't have to "pull" water..Also, I'd have the intakeU tube outside of the overflow, in the tank, not in the overflow.
 
miles o'reef

miles o'reef

Member
You could drill 3 holes in the bottom of the tank and insert pvc pipes with elbows. On the end of one, put a bulkhead screen to serve as your drain/overflow and the other two can serve as your returns. You can hide these pipes with LR.
I saw this done on a vendors website. I don't think links are allowed so do a web search for "skylab".
Miles
 
lagatbezan

lagatbezan

Member
Thanks misfit, thats exactly what i was thinking of doing!
How do you have the pump attached to the overflow?
how is the system working out? are you happy with its water movement?
thanks so much.
 
misfit

misfit

Active Member
all i used to mount the pump was a couple 10-32 plastic screws through the plaxi and drilled and tapped the base of the pump.I am very happy with it,the mag 7 keep works great, my water has really looked clearer since i did that.plus every think is hidden behind my corner box,it lookes so much cleaner no power head cords, nothing. I try to post a pic of the tank how it looks.
 
timo

timo

Member
I don't think pumps will pull water up. There needs to be a prime in the pump. I can't think of how to do this with the pump above the water.
And nice flow-thing, misfit, how's it been working?
 
timo

timo

Member
Priming means to have water already in the pump itself before turning it on, so there's something to move, as they usually won't pull air. There are many ways to do this, usually by incorporating an endcap at the top of the plumbing that is filled with water then screwed back on tightly.
This does not need to be done with a submerged pump, as they're already filled with water. I believe the term for air not being moved by an impeller is cavitation, which can happen to even a submerged pump or an external one that has air being pulled into the system somewhere, usually at the endcap that is for priming the pump.
I'll look for a pic
 
timo

timo

Member
The topmost tube is the intake for the pump below. The part where the tube goes over the tank is split in two. One into the tank, and one an open tube with a threaded endcap. Before turning on the pump the first time I had to fill the tube from the open part, and screw the cap on, as the pump would not pull water up and over the rim of the tank. There may be a bit of air in the lines immediately after startup, but the water I put in there keeps the ball rolling.
Priming the pump only needs to be done once, even if the pumps turns off.
 
lagatbezan

lagatbezan

Member
Thanks TimO fro all the info and the pictures! they were great.
I was thinking of having the pump sumberged in the overflow, pushing water up. what do you think? Also what size pvc tubes do you recomend i should use?
Again thanks.
 
timo

timo

Member
Pipe size depends partly on what pump you plan to use. 3/4 is good but for flow nothing beats 1 inch.
Try to avoid 90 degree turns in the tubes, try 2 45's (I wish I had!)
Do a search on a product called "scwd", or sqiud. Great for non-electrical alternating flow. Max GPH@ 0 head on those is 1440. There's one in my pics as the return from the pump that's seen, which is a closed loop. It's the black thing where the flex tubes are.
Submerged pumps are great for your application. It's when halides are thrown into the equasion that submerged pumps just add too much heat to the tank.
External pumps tend to be more powerful, too.
Anyway I can help you get great flow, I'll try.
Tim
 
misfit

misfit

Active Member
my system works great i probley should have gone with a mag 9 but it works well.i think i have plenty of water movement between the closed loop and the 2 canister filters,ive put it at about 1200 gph in a 120 gal tank.The loc line is great every couple of feedings i just tweak the hoses a bit which changes the movement and now i wont have any fish or anemones sucked in to a powerhead, thats why i started this project i ended up loseing a huge long tip to a PH.Heres a few pics sorry it took so long
 
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