drilled tank questions

[dpatte]

The tank I recently purchased is drilled, with two large holes on the right side (it was previously used for saltwater). Im new to drilled tanks and terminology, so I don't know any of the terminology. If I use the incorrect terminology, please correct me.

I won't be using a sump system, and only want to draw water from one end of the tank with a mag 18 pond pump, then direct the output of the pump so the water re-enters the tank at the other end of the tank. Without the holes, I would simply use standard input and output u-tubes and tubing to the pond pump, but figure perhaps I could use the holes since they are there. If I don;t use the holes, how do I close them?

Where in Ottawa to people get plumbing for drilled tanks, and where can I read about drilled tank plumbing fittings and their use?  

[Greatwhite]

What  you're describing is a closed loop circulation system. 

You can get plumbing for your holes at Lowes.  Be sure to get PVC, not ABS.

If you don't want to use the holes, I believe there are plugs available.  Otherwise, get appropriately sized bulkheads (threaded fitting that goes through the hole, and tightens on) and whatever pipe and fittings that will suit your needs.

I like the flex PVC and barbed fittings that push into the pvc tubing.  You can use hose clamps to tighten the hose onto the fitting if you like, but it's designed to be a nice tight fit...

Google "aquarium standpipe design" for ideas on how to build your overflow.  People will talk about Durso, Stockman, and others.  I've only ever used Durso (because that's what came with my aquarium)...

[bitterman]

David,

What is the size of the holes? You need a bulkhead to match the hole size.

PVC is the best but ABS is often used as well.

You can easily made a spray bar on the one side the take to flow back to the intake. If you need a hand let me know and we might be able to make something work. This is an example of a PVC spray bar I made but you could do it on the end as well.



Bruce

[dpatte]

I have bulkheads, but I think i should change the gaskets. The bulkheads seem to be threaded inside as well. I simply want to run the equivalent of a u-tube out of one of the two holes then down to my pump then return the water at the other end of the tank.

Is there such a thing as threaded piping I can buy?

[Rybren]

You can pick up threaded adapters - male thread on one side and female slip on the other. You can then glue or friction-fit regular pipe into the adapter.

Use glue if the fittings are external to the tank.

You can pick up ABS adapters almost anywhere.  Lowes and many pool/spa shops and some LFS have PVC adapters.

FWIW, I have a mix of ABS, white PVC, and grey electrical PVC in my systems.

You may not have to change the gaskets.  There are 3 key things to check when using the bulkhead:

1. The gasket and glass must be clean
2. The gasket goes between the flange and the glass, regardless of whether the flange is inside or outside of the tank (NEVER PUT THE GASKET BETWEEN THE NUT AND THE GLASS - it will crinkle the gasket and cause a leak)
3.  Don't over-tighten the nut.  Hand tighten and then a 1/4 turn with a wrench

[dpatte]

Thanks for your help. The tank has 2 bulkheads on the right side of the tank. a few inches below the waterline. They have internal threads 1.75 inches.

I will assume I can get 1.75 threaded fittings to slip, and step down the size to the tubing size I will use for my pump. I assume I should also use that special plastic tape on the threads to ensure they don't leak. Is this correct?

How long after gluing is the plumbing safe, and can glue not be used inside the tank (which is currently not filled)? 

[Rybren]

You might have to look around to get the adapters if you want to go with PVC - selection is rather limited in Ottawa.  I did manage to pick up quite a few pieces at the pool/spa place down the road from Aqua Valley.  I don't recall the name of the place, but it's next to the big Childrens' play place.

ABS is much easier to find.  I believe that most black bulkheads are ABS as well.

I use the Teflon plumbers tape on the threads.

Once the pipe solvent is set, you can use the pipe right away.  The glued joint can be supmerged in the tank without issue. I would rather use a friction fit for inside the tank (a wrap or two of the teflon tape will help the seal) It would make disassembly much easier.

[lucius]

You might have to look around to get the adapters if you want to go with PVC - selection is rather limited in Ottawa.  I did manage to pick up quite a few pieces at the pool/spa place down the road from Aqua Valley.  I don't recall the name of the place, but it's next to the big Childrens' play place.

It's Mermaid Pools.

[Rybren]

Thanks