Closed loop idea

[topofsteel]

I have a 115 gallon tank with an overflow drilled for supply and return that I'm about to set up. I'm not really in the position to take it and have it drilled for a closed loop system. But it has a custom canopy with extra room.
What I was wondering is if I could put a pump in the canopy to suck water up and direct it back into the tank. Many pumps say they need to be submerged, I would need one that could start dry. Has anyone done this? Does this sound like a good/bad idea? Are there any other considerations you can think of? Thanks.

 

[shrimpy brains]

I don't think you will find a pump that will suck water. You could submerge the pump in your display (build a holder out of pvc if you like) and hide it behind you live rock!?

 

[geoj]

There are many pumps that work this way. You put them down on the floor and though suction draw water out of the tank and through the closed loop. I have done this for a chiller. The hard part is even the pumps that say they are self priming, don’t always prime because of how you may plum the system. So having a priming port at the top to fill the lines with water is a must…

 

[acrylic51]

Running your CL this way truely isn't a CL. Being that if for some unknown reason your main circulation pump would fail I would think running it this way you run a very good chance of destroying your CL pump......It's not hard to drill your own tank with a couple simple tools.....But yes you can make a pump "suck" as described.

 

[topofsteel]

acrylic51, how can I drill my tank? And what would a recommended setup be, pull from the bottom and return into the top of the back, in 2 places? And can the closed loop pumps be suspended right below the tank, above my sump? Thanks.

 

[acrylic51]

A true CL would have it' own supply of water to the pump basically creating a "closed loop" meaning from bulkhead and water contained in pipework back to the tank....with you relying on the overflow to be your supply for your CL if something were to fail or happen to your overflow level you'd starve your pumps.....You have to decided what size pump and plumbing your working with....on my last setup I was using the OM 8Way for my CL and I had 2 2" drains(bulkheads) feeding my pump and I ran the returns from the OM overtop the tank....your returns could be done many ways IMHO.....
As far as drilling your tank you can do it with something as simple as a Dremel or Rotozip.....A long time back I had posted the bits you can get from Harbor Freight to drill your own tanks and the bits are inexpensive.....Technically you don't drill, you grind away the glass. Super easy job, takes alittle time and patience, but very cheap and easy to do. If you look up Harbor Freight and look up diamond bits, you should find them.......What you would do is trace your bulkhead pattern onto the glass in the desired location and slowly start your drilling.....I use a water hose on a slow trickle to keep the area cool. Works like a charm.....I'll see if i can dig up some old pics of the bits........

 

[topofsteel]

My original idea would have drawn from the display tank, it remains at a constant level, right to the top of the overflow, even when the system shuts down. But I really didn't think that was a great idea anyway, pumps and water up next to my lights. I would like to check out your old posts, and mine. Where did they go? I was on hiatus for a couple of years and they redid the site. I'll check out harbor freight, thanks.

 

[acrylic51]

I have a pic of the back of my other setup, not a real clear pic of the 2 2" bulkheads feeding my OM's, but it's a real simple operation to drill the tank actually. Your idea of drawing from the tank would work, but you might have issues priming the pump to get it started and then in the event of a power outage it might not restart on it's own. The problem with your idea is being able to initial flood the pump volute with water doing the up and over the top of the tank. By having bulkheads in the tank your letting gravity take care of flooding the pump....I'll see if I can find the old pic to give you an idea.

 

[acrylic51]

Here is a couple of pics and again not the best pics, but gives you somewhat of an idea what I'm talking about. Again the pics aren't the greatest, but I would almost think you'd need a strong pump to pull to start the suction.

 

[topofsteel]

I would like to see the pictures if you can find them. I checked out Harbor Freight, they have really cheap diamond bit sets. I've used a dremel in the past, I remember it zipping out of control across the wood. I would clamp a plywood template in place before trying it. I would need 4 holes (2@1" & 2@3/4") in 3/8" glass, how many bits would I need, and how long do you think it would take. And i decided the supply and return should all be on the back, I wouldn't want to deal with sand getting in the system. I'll just have to come up with some creative plumbing. I also saw a device that alternates the return to simulate tides, what is that called? Thanks for your time.

 

[acrylic51]

Here's a pic of the bits.....you should be able to do all your holes with these 2 packs of bits easy....The Black case with all the little different bits in is what you would use to get your hole started and you would work the hole wider and wider till you can easily it 1 of the bits in the yellow pack into the hole and grind the hole to the correct size....HTH

 

[acrylic51]

Sorry for whatever reason the pics didn't show up.....here goes again