Closed loop or not.....

[NEReef]

I just bought a 350G acrylic tank off craigslist and it has three holes drilled in the bottom for what I assume are a closed loop. I have very little experience with a closed loop and was wondering if it was worth it vs powerheads. Also keep in mind the tank will be viewable from four sides so I dont really want loks of powerheads visible in the tank. Should i just put bulkheads in the holes and cap them off? Thoughts on the best pump to run closed loop if i go that route? It will only have 2.5-3' head then whatever restriction comes from the piping so it wont need to push a high head. Thinking high flow low pressure?? Thanks for the input.

[108reefer]

The closed loop is a great way to go - I had many different power heads in my tank over the years and finally went to a CL and haven't been happier since! a 350 is a decent sized tank so you will need a larger pump to really push the water around - another consideration is what you are planning to grow in there and how you do your aqua scape - but I would think a minimum of a reeflo - or dolphin 4600... JMO.
Good luck, and hope you do a build thread on this!

[NEReef]

Originally Posted by 108reefer

The closed loop is a great way to go - I had many different power heads in my tank over the years and finally went to a CL and haven't been happier since! a 350 is a decent sized tank so you will need a larger pump to really push the water around - another consideration is what you are planning to grow in there and how you do your aqua scape - but I would think a minimum of a reeflo - or dolphin 4600... JMO.
Good luck, and hope you do a build thread on this!

Ya i will do a build thread I am just trying to get some of the groundwork done before i get posting. I am looking at a reeflo hammerhead but i have heard both good and bad about the seals issue... kinda scary to think about. but it pushes 6000gph for 355W not too shabby.

[sirreal63]

If it were mine, I would not run the closed loop, 6000 gph for 355 watts is insane. If the tank has a center overflow, 4 Tunze 6105's would allow you have a controllable 13,600 gph of directional and varying flow for a max of 140 watts. Place them on the overflow and you have more than enough flow. With only two outlets it gets hard to place the flow adequately in the tank. Running the cabling is easy too, in a dry pipe in the overflow, no wires in the tank.

[NEReef]

I was thinking about the tunze idea on the overflow. So I am kind of stuck with some of the things that the tank came with. The overflow has just 1 big bulkhead in it like 2-3" wide. There is another section right next to the overflow that is a dry box i believe it goes all the way up to the brace on the top and is drilled out through the bottom. I plan on running all the wiring for the lights etc down this and maybe even my sump return up it. Because it will be in the center of the room i want to eliminate all wires. Hmmmm i guess i could use the bulkhead holes in the bottom of the tank to run piping up to the top of the tank to hide more power chords in and then just hide them with rock pillars so you cant see them.....

also here is a pic of the tank with the closed loop holes on the bottom.

[sirreal63]

I just looked at the other pics in your other thread. You can still use the closed loop, but I wouldn't use it for all of the in tank flow. Given the odd layout you could use a pair of 6105's and a pair of 6095's and that would save a little of the budget. It's a unique layout and has great potential. Hiding the cables should not be an issue, but one thing I would do is make sure it will be easy to service the pumps.

[NEReef]

how much service do they require? Just like a cleaning every few months? can those all be put on a controller as well? i think that a wavemaker/ feeding mode functionality would be nice to have.

[bongarone]

Does a closed loop system really only move as much water as it pumps through the pipes? What about the venturi effect as the water is returned to tank?

Closed loop vs. propeller heads is apples to oranges, it seems. Can anyone elaborate?

[sirreal63]

Service interval varies, I usually go every six months before I clean my Tunzes, but it does vary. Yes most controllers can control them with the right module, but I prefer the separate control. Either will work, it is a matter of preference. A wave is more of a challenge with the center overflow, but I think it would be possible, Roger in the Tunze forum here would be the right one to ask about that.

[Dustin1300]

I have a 600 gallon build I'm currently working on and I'm going to do a closed loop BUT the drain will be a standpipe in the overflow and the outputs will be in the back overflow (currently tapped for 3/4" loc-line) and through a few seaswirls I'd like to put in place. Outside of that return will provide flow and 2-4 MP 60s. With the power of some of the new PHs these days, no use in relying solely on a closed loop based on some of the risks below. (You also have to consider power consumption mentioned by sirreal63. An MP60 puts out 7,500 GPH at 60 watts, an Reeflo Gold puts out 5500 GPH at 330 watts with a 4' head pressure) I just think the sea swirls add some additional water movement that is worth the investment of a more power friendly Reeflo Dart pump!

I don't like holes in the bottom of the tank because you have a large risk of a leak or possibly having to DRAIN the tank! (Bad valve, bulkhead, plumbing fitting, etc) I just can't imagine to have to drain an established 600 gallon tank later down the road. Large or small leak, that's a PITA and your going to have to tear the tank apart.

[NEReef]

Originally Posted by Dustin1300

I have a 600 gallon build I'm currently working on and I'm going to do a closed loop BUT the drain will be a standpipe in the overflow and the outputs will be in the back overflow (currently tapped for 3/4" loc-line) and through a few seaswirls I'd like to put in place. Outside of that return will provide flow and 2-4 MP 60s. With the power of some of the new PHs these days, no use in relying solely on a closed loop based on some of the risks below. (You also have to consider power consumption mentioned by sirreal63. An MP60 puts out 7,500 GPH at 60 watts, an Reeflo Gold puts out 5500 GPH at 330 watts with a 4' head pressure) I just think the sea swirls add some additional water movement that is worth the investment of a more power friendly Reeflo Dart pump!

I don't like holes in the bottom of the tank because you have a large risk of a leak or possibly having to DRAIN the tank! (Bad valve, bulkhead, plumbing fitting, etc) I just can't imagine to have to drain an established 600 gallon tank later down the road. Large or small leak, that's a PITA and your going to have to tear the tank apart.

Ya i agree if i were to build/buy a new tank i wouldnt put the holes in the bottom. But since i got this one used i am kinda stuck with what ive got....

[tkeracer619]

I agree with Jack. Use some Tunze pumps.

I would also plug those holes with sch80 bulkheads. They won't leak or if you feel up to it cut out some acrylic squares and glue them down using weld on 16.

[NEReef]

Hmmm now im really thinking..... I might use those bulkheads to make some pipe stands that balloon at the top big enough to fit the dry side of a Vortech inside them then cover the pipe with rock..... I have zero experience with vortecs but I think if it can hold through 1/2" or 3/4" acrylic it should hold through pvc, right??? That way the dry side with the power cord can just run down the pipe into the stand and be plugged in. I could different height stands to get different levels of flow....

[sirreal63]

I was thinking vortech initially, but the humidity levels would be a concern, as it would be much higher than a typical installation.

[NEReef]

Originally Posted by sirreal63

I was thinking vortech initially, but the humidity levels would be a concern, as it would be much higher than a typical installation.

Ya it probably would be since it would be in a closed tube above the sump....

[Snausy]

You ever consider just welding over the holes with some patches and deciding how to plump your new tank the way you want to? I couple 3"x3" patches and boom holes are gone.

[tkeracer619]

^^^This

In case I missed it what are you going to keep in the tank?

[Snausy]

Plumb it's supposed to say. sorry the android was auto correcting. yes plug those holes with patches and start fresh