newbie piping questions - what size return - what size overflow?

[Milad]

i really liked bean's design and i like the idea of going with water movers in the tank
The tank already has two holes drilled so can i use those two holes to push water into the tank? and drill three more holes up higher to implment bean's design? all with smaller piping?

here is a drawing of what i mean:
The green pipes are the return and the red are the drain

[Milad]

btw which pump would you guys suggest?

[golf nut]

You might want to reconfigure the returns to the the tank, they are somewhat low, if the power fails you will have a flood on your hands, ideally they should return to the opposite end where they would move the surface water to the overflow box but that would alter the aesthetics of the tank. You could reduce the width of the overflow box and bring the returns up higher on the end sides to reduce the flooding issue.

[Milad]

can I not use some sort of check vavle?
http://www.plastomatic.com/ckm.html

those holes are already drilled so thats why i figured ill use them.

Originally Posted by Mr OM

You might want to reconfigure the returns to the the tank, they are somewhat low, if the power fails you will have a flood on your hands, ideally they should return to the opposite end where they would move the surface water to the overflow box but that would alter the aesthetics of the tank. You could reduce the width of the overflow box and bring the returns up higher on the end sides to reduce the flooding issue.

[golf nut]

I removed the word check valve from my dictionary, Murphy advised it.

Do you have pictures of exactly what holes you have and where?

[Milad]

MR OM i hear what you mean, one more thing that could go wrong
The current holes are about 8 inches from top and about 4 inches from the side
The second rendering has the green pipes going through the current holes

Bloodasp, wouldnt that just make it drain the same water that was returned back up?

[golf nut]

Do you plan on having the display as a peninsula, or is it just the way it is drawn. what diameter holes are drilled at the locations you gave.

[mark]

Originally Posted by Milad

The current holes are about 8 inches from top and about 4 inches from the side

As MrOM cautions re low return holes

To find the size of sump you'll need to handle the just back flow if you lost power and the check valves not working, it's the 8" x the width x the length of tank divided by 231 for gallons. You'll probably find it 50+ gallons.

Not ideal but could still use the holes for return, just have your return line go up to the top of the tank then back down to the holes and have a small siphon break at the top. Line can extend fr the siphon break to over the tank.

[Bloodasp]

You could put a 90 degree elbow on your return going up. not sure what it will do to the look of your tank but worth trying in your rendering. The check valve could work too and just do regular maintenance to make sure it is not failing.

[kien]

oh hey this is where you guys all went!

All you need are two drains to run a herbie as already mentioned. One for the main and one for the emergency. It looks like you have a third in your overflow box? I'd either cap that off and don't use it, or 'T' two of them together as your main and use the third as an emergency. Another option is to use the third as a second emergency which I think you were planning but that is a little overkill. Nothing wrong with that though I guess. If your drains are 1.5" it will be very hard to overflow a wide open 1.5" drain unless your return pump is rated for something insane like 3000gph (don't forget about the loss of flow due to elbow, head and such), which it probably won't because then you're pushing way too much water through your sump in my opinion

Another thing, those holes that you are planning to use as returns, I personally would not use them. They are a bit low and will probably cause overflow in your sump (unless your sump is massive, like 200g and only run at half level) if the power goes out. You can throw a check valve on those but you will need to remove those check valves and clean them frequently otherwise they will gum up with junk and eventually fail. Or worse, what happens if a snail gets in there? If it can happen imagine that it will :-) It may not happen today or tomorrow or next month, but that's the problem with Murphy right? You just don't know when.. Instead, I would run your return up and over the edge of the tank and while you're at it I would run the return pipe to the other end of the tank (opposite from the return overflow).

There's really no right on wrong answer really, whatever you end up doing, if you get water into the sump and out of the sump then it is working. It all boils down to how efficient you want to make it, how much maintenance you want down the road, how much of a failure alleviation factor you want to put in, etc.. Based on my experience with peninsulas that's what I would do :-) There are a crap load of them on canreef, just do a search and you'll find them :-)