Closed loop help needed *UPDATED*

J

JSB

I've got what I believe to be a good closed loop set up. I feel like it's one problem after another with this project. Anyway, why can't I get the pump to move water. I filled my prime tube yet it never fills up, and kicked the pump on. It just makes horrible sounds. I think it will catch up here in a second, but no it doesn't. I'm assuming it's having trouble pulling the water up out of the tank isn't it. I'm going to take a deep breath and put it all away, and have a beer or something before I sell this entire setup and throw in the towel. If anyone can tell me where I'm going wrong I'd appreciate it. Thanks! :sad:

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Perhaps if you reduce the input pipe size to 3/4". You really just have to double the output pipe diameter in order to get the posted gph from a mag pump.

Cheers!
 
Your problem is air. If the air was purged from all the pvc then the horrendous noises wouldn't be there. Since you're bringing the PVC up over the water line, all you can do is suck air into the pump. If everything was submerged and purged of air, it should work fine. if you're concerned about additional heat from the pump, you can run your pump externally and make 'U-tubes" and keep the pump under the water level of the tank.
 
Your problem is air. If the air was purged from all the pvc then the horrendous noises wouldn't be there. Since you're bringing the PVC up over the water line said:
I agree with Russ here too and to explain a bit, it will be *very* difficult to get a pump to function properly with it above the water line without using all sorts of *tricks* in the horizontal lengths and rise lengths of the tubing. Even then, it will be problematic. The real issue is that the amount of water to air ratio in your prime line is insufficient to keep the pump sucking/creating a vacuum strong enough to pull the water out of the tank before it hits another pocket of air. This would not be a problem at all if the pump were able to dry start/create a suction without water in it, but there are only a very few pumps (and no small ones that I'm aware of) that will create enough suction to dry start a water flow of even a small (1-2") rise of water. With the pump below the water line on the outside, gravity will work with you instead of against you in trying to help keep the line full of water once it's started. Alternately, you could put the pump (if submersible) into the water and then it would work perfectly too (but you would have the additional heat generated into the water). I'd be glad to discuss it more with you if you want to drop me a PM and we can phone chat a bit. In any case, don't give up on it yet... I can't tell you the amount of PVC I've had to recut/glue/etc while plumbing our largest tank. :oops: HTH
Doug
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Okay. I think I'm understanding this now. Plus it also proves what I was testing last night. At first I thought I had an air leak. So I took the pump from the union openings and stuff the intake just barely in the water. It was only a few inches of pipe but still the same result. Couldn't suck the water, but as soon as the pump started to submerge into the water it would work fine, even when I pulled the pump back out of the water. It would continue to pump. So I've either got to reconfigure the plumbing, or I'm thinking (I haven't tried) dip the pump into the tank to get it going. I'd be interested in seeing some closed loop systems for ideas.
I'd really like to avoid running pipe down the back of the tank. First of all I have no room, and secondly I switched to RR to avoid doing that.
Thanks for the help, and if you have anything else in mind that could help please feel free to share.
 
JSB
So I've either got to reconfigure the plumbing said:
Even if you get the pump running the first time, anytime you have a power glitch and/or turn the pump off, it will have to be re-submerged to start it again and it's likely to stop and then not be able to restart without manual intervention and it will damage the pump from the continual inability to pull water while running. You might could build a small acrylic pump holder that hung off of the back edge some way and only lowered the pump to water level so gravity wouldn't be fighting you.
Maybe someone else who has managed to get a pump working when it's higher than water level will be able to share some ideas too. Sorry I couldn't be more helpful in that manner.

Doug
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Aquarium pumps are made to be fed water, not suck it. Even in an over top setup you still have a siphon effect feeding the pump below. Having it above the water line like that is a bad idea.
 
@mwolek wrote:
Aquarium pumps are made to be fed water said:
I 100% agree with Mark here.. Almost ALL aquarium pumps are designed to " push " water not " pull " water. This is why you see the pumps rated for flow based on Head Height.

The MAG will have to sit below waterline or you will not get it to work, or if you do, the flow will be greatly reduced and you will be destroying impellors all the time.

My .02 cents

Mike
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Well It's going to be a tight fit, and a pain in the neck now that the tank and sump are full, but I have enough room to run 3/4" pipe down the back of the tank. I guess I have another new project to add to this build. Thanks everyone.
 
Jeremy,
I couldn't tell the size/brand of the pump you will be using, but if it's a *non--presure* rated pump (like most submersible pumps), you will loose a large amount of water flow by using only 3/4" piping for a closed loop. I would hate for you to spend a large amount of time (not to mention $$) only to find that you don't get a lot of flow from the pump due to the small piping. There is a calculator on reefcentral that will help decide how much flow you will loose based on the pipe diameter after you select the pump you are using (or one similiar) and the length of the PVC, number of elbows,ect that you can play with to see what the effect of the pump will be. Also, when the pumps are restricted on the output size, it generally makes them work harder and thus generates more heat that you have to deal with some other way. Here's the link:
http://www.reefcentral.com/calc/hlc2.php
I don't want to discourage you, but do some calculations to see if you feel it's worth the time/effort/result that you will get. I think you will get more flow from a couple of Maxijet 1200's than you might get from the other method. I know it's discouraging to build it and it doesn't do what you want, so I thought I'd at least mention the calculator if you hadn't seen it before. HTH
Doug
 
My sump return is a Mag9 and its plumbed with 1.5" which tee's to dual 1" intels to the tank.

How much room do you have between the wall and the tank? Looks like your working inside a canopy as well? May just want to use a couple power heads or a stream or 2.
 
Thanks Doug, but I've bought a ton of loc-line and a pump to setup a closed loop, so I've got to finish it. You know how it is when your set on doing something. The pump is a QuietOne 3000. It moves something like 750 gph. The pump won't be in the water, so heat won't be an issue. I lose 100 gph going from the 1" to 3/4 which isn't what I like to hear. I might be able to fit a 1" pipe but it would take a little more work than I feel like putting in. My loc-line is 3/4" anyway so at least it will all be the same size now. What if I Y-ed the output real close to the pump and run 2 3/4" pipes intsead of one. Would that make a difference?
 
@mwolek wrote:
My sump return is a Mag9 and its plumbed with 1.5" which tee's to dual 1" intels to the tank. How much room do you have between the wall and the tank? Looks like your working inside a canopy as well? May just want to use a couple power heads or a stream or 2. said:
I was working inside the canopy but quickly found out that wasn't working. I can fit a 1" pipe behind the tank, but not the stand. I'd either need to move the tank stand out a little or cut out a little bit of 2x4.
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@JSB wrote:
....What if I Y-ed the output real close to the pump and run 2 3/4" pipes intsead of one. Would that make a difference? said:
While it would make a difference, it *might* actually be worse since the pipe friction would be double the original too. It might help if you can use a 1 1/4 to 1 1/2 inch tee and then step each side down to 3/4", but my feeling is that it would actually be slower. Maybe someone else will clarify on a split line flow/head loss.
Doug
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For what it would cost in PVC I would try it personally.

I would also probably try taking 3/4" up to the tank and see how it works. Worst case your our $10 in PVC and a little time.

Of course the right thing to do is train the tank and move it away from the wall a few inches :p Don't worry I don't think I would do it either, I'd scrap the locline and buy powerheads before actually doing something logical like moving the tank lol...
 
I hear you. I just hate shutting every thing down and start emptying the tank. I wish I could move 90 gallons plus the tank, the stand and canopy in one quick nudge. :lol: The problem with moving the tank out is it's kind of in a hall way. It's hard to explain but there is a wide hall way between the bar of the kitchen. It leads to the living room and to another hall way to the bed rooms. I'll take a pick and show you. A half inch shouldn't hurt though. Thats about what I need to get the 1" pipe in. :wink:
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Well I finally finished rebuilding the closed loop system, and yet again I'm a little disappointed. I originally wanted 4 outputs but that really killed the power of the flow. So I knocked it down to two, and it's okay a best now. I ended up going with 3/4" sched 20 piping. I also am unhappy with the noise level. It went up quite a bit. I believe it's due to the fact the pump is external, and the pipe is touching the wall causing a vibration. I managed to put some rubber between the pipe and the wall, but it only knocked out about half the noise. It's still pretty noticable.

Here are some shots of the setup. I'm thinking I need a more powerful pump. This one pumped 750gph, but I think I've got closer to 450gph with the piping, height, and elbows.

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HI Jeremy,
if you'd like, my .02 cents for the second time.
First, at least the pump is working now instead of cavitating all the time.
With that said.... I agree, if ANY plumbing touches a wall or the cabinet itself, more noise from the pumps' vibrations will be amplified to the point of annoyance. Insulating the pipe will not stop the noise, just muffle it some. You need to get the pipes off the wall all together. The other thing I see is you have the pump seated on a wooden shelf which looks to be attached to the wall. I like my Japanese Iwaki sitting on a 1/2" piece of styrofoam and seated on the floor which reduces the noise to the point of not hearing it run.

Looking at a picture of your locline. Where you installed the first Y on each side, you do understand that first nozzle will always produce a sizable amount more of flow than that of the second one due to it being a Y in place of a T, right?

All-IMHO
Mike
 
Thanks mo. I like the feed back.

I knew the farther exit points would have less pressure, I just wasn't expecting the trickle they had. I've since switched to two exit points. This helped. They feel like they're close to my maxijet 900s, if not the same. I guess I'm going to have to try and budge this thing off the wall some. The pump is setting on a shelf that I mounted to the back wall of the stand. I was attempting to keep the pipe length as short as possible. I'll give the foam a try though. Shoot I'm actually thinking new pump quite honestly. I was wanting more pressure. :wink:
 
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