Minimum Clearances when drilling an overflow

[ensquire]

Originally Posted by sphelps

You can try using the smaller drain for the main and the larger one for the back up. Make both as large as possible by using thinner bulkheads if possible (although I'm not a fan of the thin ones)

Also an alternative for the back up is to use the smaller drain but use a larger diameter pipe than the bulkhead (if 1/2" bulkhead, use 1" riser pipe) in the overflow to slightly increase the amount of water flow it can handle. You can also use larger pipe below the back up bulkhead as well. This will eliminate most of the pipe friction and increase flow.

Lastly just throttle back your pump to match what your drain can handle.

I would use one or more of the above methods over re-drilling the tank.

Some very viable options Thank you . But I did spend like 100.00 on various diamond bits and am dying to use them .
But seriously Ill see if I can upsize the pipes on both sides of the emergency and test that out.
Since I have tirn everything down again and can't test third idea out, my question is this.
When we throttle pumps down with a valve , does this not make them noisier ??
I will start a build thread to carry these ideas on with.

[sphelps]

Originally Posted by ensquire

my question is this.
When we throttle pumps down with a valve , does this not make them noisier ??
I will start a build thread to carry these ideas on with.

I depends on the pump and the quiet ones do sometimes make more noise with more head pressure but not always. In general a pump shouldn't be any nosier but different people have different results. When you close a ball valve it just increases the head pressure which is the same as lifting your tank higher above the sump. In addition you pump should use less power with more head pressure.

With the tank already assembled and already drilled I personally wouldn't try and drill a larger hole on top of a smaller hole unless it was absolutely necessary, and I've drilled a lot of tanks before.

[ensquire]

Thanks sphelps , I have to order a few fittings etc, as usual this isn't just done by driving to local store. LOL Good thing about it is that it gives me a chance to evaluate my options and no rushing into anything.
I will take the opportunity to paint my stand and move it to my office.
At this point I'm going to increase the pipe on both sides of the bulkhead and play with the outflow and see what that does for the situation.
I am moving everything else over to a build thread here :
http://www.canreef.com/vbulletin/sho...996#post596996

[lastlight]

When I said too close together I just meant vertical distance between drain intake and emergency intake. I'm not sure how some people tune their valves so exactly but I've always found the water level will creep slowly up or down no matter how careful I am. So I tune it so a tiny bit trickles into the emergency always. If the emergency was too close to the drain (water height above the drain was too low) it might suck air. All I meant but maybe I misunderstood your issue.

I'd also try and use the smaller hole as your drain before drilling though.

[ensquire]

Thanks lastlight , at this point it is all taken down for painting and upsizing of the pipes. I have 2 or 3 easy to try options to try and fix this including changing drain and emergency pipes and because of all the advise I am not in such a rush to do any drilling.

Appreciate the input.

[ensquire]

Updated starting here.

http://www.canreef.com/vbulletin/sho...18&postcount=9