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

[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?

[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.

[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.

[Milad]

yes its a peninsula
its going to be used as a "wall" between living room and office
i believe the hole are 1.5in i think.

[golf nut]

Stick with the first plan aq-rear-1.jpg unless you are prepared to drill more holes, if the holes are drilled for 1 1/2 bulkheads and you use a nominal return pump then the Herbie drain will be more than adequate, if they are only 1 1/2 holes in the glass then I would get it drilled properly in which case you have a clean slate to do as you wish.

[Milad]

is 1.5 a weird diameter? im not 100% sure what they are im going by what i remember when i saw the tank. I wont have it until 1.5 weeks from now. They could have been 2"

I just want to make sure there is a backup for the backup. I would die if 180g of water went everywhere!

bloodasp suggestion doesnt look to bad i just dont know if its going to pull in the same water it returned or not.

i could just plug the existing holes and drill 3 new holes...

this is hard setting it up as a peninsula, very little to work with.

[golf nut]

Peninsulas have their share of problems but principles stay the same, get the hole sizes then we know what you have to play with.

[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 :-)

[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.