where to drill?

[outtafocus]

I will be drilling my tank within the next week and a bit. I have two choices of where to drill the hole for my overflow exit.
My tank is made of 1/4" glass all around with a 1/2" bottom.
Question is, should I drill the 1/2" straight out of the bottom of the tank, or drill the 1/4" back panel and 90degree out of tank to flex tubing?

Drilling the 1/4" will be alot easier, but will exiting out of the back of the back reduce my flow?
I will be using 1" pvc so the hole for my bulkhead will be 1 3/4".
What do you think?

[BT05]

Drill the bottom and build an overflow box around the hole. I do't know the size of the tank but 1/4" glass doesn't need to be weakened any further by drilling a large hole. Also, you will lose flow if you drill through the back regardless of the type of plumbing you use.

[Delphinus]

I've forgotten what you told me was the overall gallonage of the tank. Size could play a factor in your decision. Ultimately though, bottom or back, we can drill either, so no worries there. I don't think there's a substantial difference if you go with the back versus the bottom. In this case, one is going to be quicker to do than the other. But don't worry about that, once the job is done, it's done, so I guess it's just a case of whatever you think will suit you better.

From the 1/4" I assume the tank is not all that large, maybe 20-30 gallons or thereabouts. On that size of tank I'm not sure I'd be too worried about flow restriction, we're going to go with 1" bulkhead so we're not talking about 2000gph here.

If you think about how a durso standpipe works, you could build a cup style overflow drilling out the back, have the drain external to the tank, all that you have inside the tank is the 90 degree elbow. This is a keen way to do things. I'd draw up a diagram and post it but it would take me too long. Instead I'll see if I can find an example online already of what I'm talking about. The advantage of this would be the quietness of the durso without the invasiveness of the large standing pipe inside the tank, and you could have access to the whole bottom footprint of the tank for aquascaping (ie., no notched corner, which sometimes can be a pain).

If you were to drill out the bottom and go with the notched corner overflow, it would be pretty easy. You couldn't go with a Durso though. If noise was an issue you'd need to go with a Stockman style overflow. They work plenty fine.

That said, I have a 20g with the notched corner overflow and I just use a standing pipe with a strainer (no Durso or Stockman on my 20 although I use a Stockman on my 90). Because the level drop is not very much the gurgle sound is pretty much not noticeable anyhow. So this could all be a moot discussion.

I guess it depends on how tricky you want to get. 1/2" glass is a lot harder to break than 1/4" (although there are never any guarantees when you drill). But I've broken 1/4" a few times now (once I overtightened a bulkhead ... snap. Another time I was trying to wrestle some plumbing into an awkward spot, and I bumped the bulkhead, and snap. Another time I was wiggling some hose off one of those hose barb things and the wiggling snapped the glass - hole was too close to an edge I guess). That's about 3 times out of .. hmm I've probably drilled 1/4" about 20 times. So the failure rate is .. um .. sort of low but definitely not zero. I haven't yet broken 1/2" glass (but there's a first time for everything!!!). Not trying to scare you here, mind you, just thought I should mention that drilling glass isn't completely risk-free. "Most" of the time it's fine.

[Delphinus]

PS. I promised I'd search for an example of the exterior Durso style standpipe. Here's Zephrant's (from RC) page where he sells the same style of overflow: http://www.barraquatic.com/overflows.php

[Invigor]

Originally Posted by Delphinus

PS. I promised I'd search for an example of the exterior Durso style standpipe. Here's Zephrant's (from RC) page where he sells the same style of overflow: http://www.barraquatic.com/overflows.php

those are pretty neat. I was going to do that but decided against it and went with the el standardo 2 panes of glass in the corner with a hole in the bottom :| for the sake my tank can be up close to the wall :P

[outtafocus]

FYI, I am going straight down, through the 1/2" glass. I am using 1" pvc which should give me adaquate flow in a 25gal cube.

25gal cube + approx 15gal cube sump + 11gal external display refugium
= approx 51gal total. Not bad considering my plan was to have a small system for my apartment.

I will be placing the refugium on a seperate stand next to and about 4" higher than my main display tank. Water will enter the fuge via a T off of my return line with a ball valve to adjust flow. Water will then fall back into my main display through a 1" bulkhead drilled into the side of the fuge glass and plumbed over the edge.
This way all pods that grow in my fuge wont be chopped up in a pump before they become food for a possible(???) distant future mandarin.
What do you think?