Closed loops

[FishWife]

OK; we are trying to make some final decisions on closed-loop construction.

 

We have these specific questions, and are hoping to get some really specific answers. I don't know why they're so elusive, but I guess we've gotten several conflicting and generalized opinions... so, here goes!

 

First, the set up. We have an 80 bow. It's fed by a remote sump/refugium through intake/outflow thru two drilled holes in the bottom of the tank, thru a wall, and in/out of our 75 g converted tank sump. In the sump is all the skimming plus RDSB, etc. but we're interested in adding closed loops (we think, maybe two) instead of traditional approach of using power heads in the display for water movement. This is our best guide of what we're aiming for so far: http://www.reef-eden.net/diy_6.htm. Like him, we want to go over the top of our tank and down to external pumps (not submerged); like him, we're not going to drill our bow 80 'cause we're not committed to it forever. We hope to step up in the foreseeable future. So, we're thinking two modest closed loops that cover the two halves of the tank that are interrupted by our back, internal, just off-center overflow box.

 

Our questions:

 

1. Our first problem is, the author of reef-eden linked above is British, so all his pipe diameters are in mm's. Basically: what American-size diameter of pipes are best for going from the pump to the outlets in the bottom/sides of the tank? (The responses on this thread http://www.wamas.org/forums/index.php?show...;hl=closed+loop got us hopelessly lost...)

PLEASE, please don't say "it depends on the pump" without giving us an example: like, please be more specific and say "a Mag 12 with 1" outlet pipes would give six outlets" or something. Brand names of pumps and direct links would help so much (hint!)

 

2. Talk to us about outlets, and how to figure how many and where to put them. We have a Mag 24 (thanks to Jason). If we use 1" PVC going down into the tank and under the sand, how many outlets can we use in the tank? In other words, how do you figure the strength of the flow of water thru the pipes and out the jets? And, are the first outlets going to be stronger than the latter ones in any run, or does stepping down a size in the outlets (from, say, 1" run to a 3/4" 45 elbow outlet) mean that the pipe fills up and jets them all out equally? OR, should we ding the Mag 24 as a closed loop pump and go to something else? If so, why--specifically-- and what -- specifically-- would you suggest, pretty please?

 

3. We have a 25 watt UV sterilizer (thanks to WAMAS members' advice) that allows us to put 1200 gph flow through it and still kill parasites and bacteria. We own an 800 gph pump. Can we use this pump and this sterilizer and create our second closed loop? Is 800 too slow? We know it would be the smaller of the two loops, but does it make sense to integrate our UV sterilizer, since we have to have a pump anyways for it?

 

TIA for wading thru this lengthy post. We're hoping to get on with the tank SOON... if we can find our way... but are thinking maybe of bagging the whole closed loop thing and going to powerheads after all...

[treesprite]

I can't answer any of those questions, but I do say go for the closed loop. You won't have to see powerheads and you won't have powerheads heating up the water.

[jamal]

well a pump and a uv sterilizer is a closed loop. water goes in and out and back in. in reference to question 3 you may want less flow for a sterilizer of that size. you can put a small ball valve on it and lower the flow. so yes that will work. cant help you with the closed loop.

[Brian Ward]

OK; we are trying to make some final decisions on closed-loop construction.

 

We have these specific questions, and are hoping to get some really specific answers. I don't know why they're so elusive, but I guess we've gotten several conflicting and generalized opinions... so, here goes!

 

First, the set up. We have an 80 bow. It's fed by a remote sump/refugium through intake/outflow thru two drilled holes in the bottom of the tank, thru a wall, and in/out of our 75 g converted tank sump. In the sump is all the skimming plus RDSB, etc. but we're interested in adding closed loops (we think, maybe two) instead of traditional approach of using power heads in the display for water movement. This is our best guide of what we're aiming for so far: http://www.reef-eden.net/diy_6.htm. Like him, we want to go over the top of our tank and down to external pumps (not submerged); like him, we're not going to drill our bow 80 'cause we're not committed to it forever. We hope to step up in the foreseeable future. So, we're thinking two modest closed loops that cover the two halves of the tank that are interrupted by our back, internal, just off-center overflow box.

 

Our questions:

 

1. Our first problem is, the author of reef-eden linked above is British, so all his pipe diameters are in mm's. Basically: what American-size diameter of pipes are best for going from the pump to the outlets in the bottom/sides of the tank? (The responses on this thread http://www.wamas.org/forums/index.php?show...;hl=closed+loop got us hopelessly lost...)

PLEASE, please don't say "it depends on the pump" without giving us an example: like, please be more specific and say "a Mag 12 with 1" outlet pipes would give six outlets" or something. Brand names of pumps and direct links would help so much (hint!)

 

2. Talk to us about outlets, and how to figure how many and where to put them. We have a Mag 24 (thanks to Jason). If we use 1" PVC going down into the tank and under the sand, how many outlets can we use in the tank? In other words, how do you figure the strength of the flow of water thru the pipes and out the jets? And, are the first outlets going to be stronger than the latter ones in any run, or does stepping down a size in the outlets (from, say, 1" run to a 3/4" 45 elbow outlet) mean that the pipe fills up and jets them all out equally? OR, should we ding the Mag 24 as a closed loop pump and go to something else? If so, why--specifically-- and what -- specifically-- would you suggest, pretty please?

 

3. We have a 25 watt UV sterilizer (thanks to WAMAS members' advice) that allows us to put 1200 gph flow through it and still kill parasites and bacteria. We own an 800 gph pump. Can we use this pump and this sterilizer and create our second closed loop? Is 800 too slow? We know it would be the smaller of the two loops, but does it make sense to integrate our UV sterilizer, since we have to have a pump anyways for it?

 

TIA for wading thru this lengthy post. We're hoping to get on with the tank SOON... if we can find our way... but are thinking maybe of bagging the whole closed loop thing and going to powerheads after all...

 

I'm working on closed loop design now as well, so I'll let you know what I've discovered.

 

1- for information on closed loops, look at the discussion forum at www.oceansmotions.com it's not very active, but the company makes closed loop devices, thus the discussion forum is only about closed loops. Look at this post specifically: http://www.oceansmotions.com/forum/viewtopic.php?t=546 it's a pretty good design, and the one I'm planning to use, though I will likely do over-the-back instead of drilling my tank.

 

2- exactly how much flow you design the closed loop for depends on what you're interestd in keeping. an lps and softie tank will want significantly less flow than an sps - 15x vs 50x, so this needs to be considered. If I remember right, you're doing a budget tank at the moment, so I'm guessing lps and softies are what you're focused on since they are easier and less demanding equipment-wise.

 

3- from what I've read, 2 1.5" intakes with 2 3/4" outputs for each of your loops are probably about the right size for the loop with your mag 24. I'd probably have the return pipe match the size of the outlet on the pump, then use a T under the sand and reduce the output from the T to 3/4" - that way the flow should divide evenly between the 2 outlets. If you try to do multiple outlets from a single run of pipe, don't forget to put an additional length of pipe at the end of the run with a cap on it to provide back-pressure for the last outlet.

 

4- the mag 24 is probably too much flow for the uv sterelizer, run the sterelizer on the loop with the 8 - I'd say 1 1.5" intake ad 1 3/4" output on that one. If you'd like a brief physics lesson in fluid dynamics, PM me and I'll send you some basic info on how pressures change when you change pipe size.

5- the only reason I know of not to run the mag pumps for your closed loops is that ive heard they are known to leak, so most people only run them submerged (though I'm having no problems with mine) and they generate a lot of heat. I went with a Sequence pump for my loop, and I'll probably buy another for my return pump. I've heard good things, so figured I'd give it a shot. I haven't hooked up the pump yet, so I can't give you a review as of now.

 

I hope that helps a little. Everything is very trial-and-error in this hobby, so good luck! If you have more questions, I'm happy to toss ideas around.

 

~Brian

[FishWife]

I'm working on closed loop design now as well, so I'll let you know what I've discovered.

 

1- for information on closed loops, look at the discussion forum at www.oceansmotions.com it's not very active, but the company makes closed loop devices, thus the discussion forum is only about closed loops. Look at this post specifically: http://www.oceansmotions.com/forum/viewtopic.php?t=546 it's a pretty good design, and the one I'm planning to use, though I will likely do over-the-back instead of drilling my tank.

 

2- exactly how much flow you design the closed loop for depends on what you're interestd in keeping. an lps and softie tank will want significantly less flow than an sps - 15x vs 50x, so this needs to be considered. If I remember right, you're doing a budget tank at the moment, so I'm guessing lps and softies are what you're focused on since they are easier and less demanding equipment-wise.

 

3- from what I've read, 2 1.5" intakes with 2 3/4" outputs for each of your loops are probably about the right size for the loop with your mag 24. I'd probably have the return pipe match the size of the outlet on the pump, then use a T under the sand and reduce the output from the T to 3/4" - that way the flow should divide evenly between the 2 outlets. If you try to do multiple outlets from a single run of pipe, don't forget to put an additional length of pipe at the end of the run with a cap on it to provide back-pressure for the last outlet.

 

4- the mag 24 is probably too much flow for the uv sterelizer, run the sterelizer on the loop with the 8 - I'd say 1 1.5" intake ad 1 3/4" output on that one. If you'd like a brief physics lesson in fluid dynamics, PM me and I'll send you some basic info on how pressures change when you change pipe size.

5- the only reason I know of not to run the mag pumps for your closed loops is that ive heard they are known to leak, so most people only run them submerged (though I'm having no problems with mine) and they generate a lot of heat. I went with a Sequence pump for my loop, and I'll probably buy another for my return pump. I've heard good things, so figured I'd give it a shot. I haven't hooked up the pump yet, so I can't give you a review as of now.

 

I hope that helps a little. Everything is very trial-and-error in this hobby, so good luck! If you have more questions, I'm happy to toss ideas around.

 

~Brian

 

 

Wow, Brian! You don't know how helpful and encouraging that is. THANKS for taking the time to respond, and you probably WILL hear from us. We're going to go over to David's next week some time to view his multi-tank system as well and get real-life help. But, this link is great. THANKS again!

[Rascal]

I wouldn't use a Mag24 externally in my living space personally. It's a great pump -- I just found it way too loud.

 

I have a used Blueline 40hd-x (identical to the Panworld 100px-x, similar to Iwakis) on sale now. It is a great pump and the noise wasn't too bad. The reason it's for sale . . .

 

I recently upgraded to a Sequence Dart. No comparison. 3X the performance for 1/2 the noise (and about 1.5x the price).

 

The Dart needs 2" intake, 1.5" outlet. The Mag and Blueline/Panworld/Iwaki will do fine with 1" plumbing.

 

If you use a manifold you will get equal flow through all outlets unless the diameter is different.

 

HTH