drain hole and return hole sizing help fix my problem

[thewire]

I have this tank but I made a mistake by having only 2 X 0.5" hole drilled instead of 1" hole. What's the minimum size for a 10g sump?

Tank size is 16"X16"X17"(H) 20g cube

 

What is my solution here? I don't think I have enough room to fit a 1" hole? I dont know??? help me!

 

 

[Coral Hind]

Use the two 1/2" holes for drains and bring your return up and over the back at the other end of the tank.

[Chad]

^yep, what I would do as well.

 

Although you could also drill the tank again high on one of the sides for the return if you dont want the return to go over the top.

[Happyfeet]

^^^^

 

Over the top and 2 drains seem to be a good solution, I wouldn't do anymore drilling down there.

 

Also the second picture hurts my head, there is an optical illusion going on there or something!

[thewire]

Thanks for the replies. So, having two 0.5" drains sufficient for flow in the sump? Someone told me before that it's not enough flow in the sump? I am at lost here..

 

As for return, should I use 0.5" or 3/4" return? Do you think a mag 3 or maxijet 1200 powerful enough for return? Any suggestion here? I think I can use a directional U-tube for return and attached a ball valve on it to prevent back flow.

 

Thanks

[Origami]

Are those holes 1/2-inch in diameter, or were they drilled to fit a 1/2-inch bulkhead (which would require a 1-1/8" hole for a standard 1/2-inch bulkhead)? I hope it's the latter.

 

If the latter, you may have enough room to enlarge one of the holes to 1-1/2 inches (to fit a 3/4" bulkhead) or to 1-3/4 inches (to fit a 1" bulkhead). Make sure that you have enough room so that the bulkhead flanges and nuts do not interfere on the top or the bottom (or with the overflow wall), though, before committing. Test the configuration out on a scrap piece of wood or cardboard beforehand to test the fit.

 

Otherwise, I'd do what Coralhind is suggesting. That is, to bring the return over the top and to use the two holes for drains. If you cut one drain standpipe two or three inches shorter than the other, and install a gate valve (not a ball valve, because a gate valve gives you more precise adjustment) on this shorter leg (outside the tank), you should be able to make a nearly silent drain system.

[thewire]

Are those holes 1/2-inch in diameter, or were they drilled to fit a 1/2-inch bulkhead (which would require a 1-1/8" hole for a standard 1/2-inch bulkhead)? I hope it's the latter.

 

If the latter, you may have enough room to enlarge one of the holes to 1-1/2 inches (to fit a 3/4" bulkhead) or to 1-3/4 inches (to fit a 1" bulkhead). Make sure that you have enough room so that the bulkhead flanges and nuts do not interfere on the top or the bottom (or with the overflow wall), though, before committing. Test the configuration out on a scrap piece of wood or cardboard beforehand to test the fit.

 

Otherwise, I'd do what Coralhind is suggesting. That is, to bring the return over the top and to use the two holes for drains. If you cut one drain standpipe two or three inches shorter than the other, and install a gate valve (not a ball valve, because a gate valve gives you more precise adjustment) on this shorter leg (outside the tank), you should be able to make a nearly silent drain system.

 

 

Yes i made another mistake in this thread lol....it was drilled to fit 1/2" bulkhead. I am trying to figure out which way is the best route to go which costing me arm and leg...:(

From what you said, I need to check if I can drilled one of the hole to 1 3/4" hole and hopefully it will not interfere with the side wall. How big of the nut of the bulkhead (1") outside?

[DaveS]

It looks like acrylic so you probably have more options than if it was glass. Two 1/2" returns is the easiest option. I would probably experiment a little with enlarging 1 or both to 3/4" or more if possible. Keep in mind that one 1" return is significantly better (not factoring in redundancy) than two 1/2" so if you have to sacrifice one 1/2" hole to make the other 1", you'll still be ahead.

 

One other option is to drill in low from the side of the tank. I can't tell what the dimensions are but you could easily get a 1" and possibly 1.25" maybe even 1.5" bulkhead on each side. Put an Street elbow inside the overflow and have your standpipe go vertical from there. Depending on space, you may need to make one hole higher than the other so the elbows and pipes don't interfere with each other.

 

Having the elbows will reduce drain capacity but it should still be significantly better than 1/2".

[steveoutlaw]

I wouldn't worry about it. It's only a 20g tank and a 1/2" bulkhead will give you ~200GPH draining? That should be plenty of turnover for a 20g cube.

[thewire]

I wouldn't worry about it. It's only a 20g tank and a 1/2" bulkhead will give you ~200GPH draining? That should be plenty of turnover for a 20g cube.

 

 

So you think I would have enough draining flow for just 0.5" bulkhead? or maybe 2 with a return on the top? Is there a guide for draining flow?