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?

[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.

[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.