Overflow dimensions

[WuHT]

i'm planning (have to submit drawings)a 150 gallon aquarium , and i'd like to know whether it's recommended that i have two overflow boxes on each corner or just one (my current stand will be better off with just one).

If i were to have one overflow, what would be the best dimensions for the overflow if i were to run the return as well as a durso standpipe ?
3" by 9" ? 4" x 8" (the overflow calculator on reefcentral says that i need 9inch linear overflow length for 600gph..but i dont know if that value includes the teeth or just the gaps)

I'm most likely running a 1 inch bulkheads (so 600gph) as my drain, and for my return i'd need a 3/4" bulkhead ..so taht means my largest drilled hole should be 1 3/4" inch ?

Help please, and thanks in advance. -- I asked 3 times on reefcentral, and my threads get buried in no time! Might as well try here as well!

:biggrin:

[mark]

The advantage of 2 overflows is you have a back up in-case on gets blocked. How likely that might happen considering you can guard with screens etc. There's also that the flow is split between two so quieter. Disadvantage is you have another overflow taking up space.

My understanding is RC calculator is for a linear weir (no teeth), so 9 inches isn't that much. It's going to be more how much footprint you need for the bulkheads, if glass tank allowance for drilling close to edges, room to get you hand in. Can also consider just going at a diagonal. I've got 2" drains so my dimensions not much help but sure someone with your sizes will post. You don't need teeth btw.

Have you thought about other types of overflows such as external, horizontal in tank, linear pipe? Standpipes other than Durso eg Herbie?

[mark]

Thinking about this on the drive in from work.

Consider a single 12" diagonal overflow in the corner with 3-1" bulkheads. Laid it out on paper but since at work don't have a 1" bulkhead in front me so guessing on footprint for nut and flange so might be able to go smaller. The bulkheads would be drilled 2 on the diagonal face, 1 in the back corner. 2 of the bulkheads, vertical standpipes for Herbies (primary and emergency) third bulkhead for return.

With this the 1" return allows less restriction, the Herbie give a silent overflow with a backup drain.

[mr_alberta]

There is no way you could run an external overflow (and I don't mean an external overflow box like a cpr)? The next time I build a tank, that's what I would do. That way you maximize the area inside your tank.

[Der_Iron_Chef]

i'm planning (have to submit drawings)a 150 gallon aquarium , and i'd like to know whether it's recommended that i have two overflow boxes on each corner or just one (my current stand will be better off with just one).

If i were to have one overflow, what would be the best dimensions for the overflow if i were to run the return as well as a durso standpipe ?
3" by 9" ? 4" x 8" (the overflow calculator on reefcentral says that i need 9inch linear overflow length for 600gph..but i dont know if that value includes the teeth or just the gaps)

I'm most likely running a 1 inch bulkheads (so 600gph) as my drain, and for my return i'd need a 3/4" bulkhead ..so taht means my largest drilled hole should be 1 3/4" inch ?

Help please, and thanks in advance. -- I asked 3 times on reefcentral, and my threads get buried in no time! Might as well try here as well!

:biggrin:

I think you should strongly consider a Herbie style system as opposed to the Durso. I've been doing lots of reading/research on this, and it seems like a much better system (quieter, safer, etc.)!

For the overflow, I honestly think it depends on what type of aesthetic you're shooting for. I'm personally more inclined toward a horizontal Calfo/"coast-to-coast" type overflow as opposed to an in-corner vertical overflow. That combined with the Herbie is "bang on"....as my British friends like to say :) In addition to looking better (my opinion), it also skims the surface of your tank like a mo-fo. And there's really no such thing as over surface skimming.

Not sure if someone has already mentioned this, but you don't need teeth on your overflow. It reduces the surface skimming area dramatically.

[Doug]

If i were to have one overflow, what would be the best dimensions for the overflow if i were to run the return as well as a durso standpipe ?
3" by 9" ? 4" x 8" (the overflow calculator on reefcentral says that i need 9inch linear overflow length for 600gph..but i dont know if that value includes the teeth or just the gaps)

I'm most likely running a 1 inch bulkheads (so 600gph) as my drain, and for my return i'd need a 3/4" bulkhead ..so taht means my largest drilled hole should be 1 3/4" inch ?

I like the two overflows for the reasons mentioned. My larger tanks had two. They were 6in. sq. inside measure. I dont like the smaller holes though. Both mine had 1.25in. drains, meaning the drilled holes were about 1.75 in. or so, depending on bulkheads.

However, on my 180 cube, I went with a single sq. corner overflow, again about 7in. sq. All these used eggcrate teeth by the way. This time I had a 2in. + hole drilled that allowed for a 1.5in. drain. I really liked that set up and the larger drain allowed for a pump size increase or not.

Just my opinion but I dont like 1in. drains. If doing so, then for sure two overflows is the way to go.
Help please, and thanks in advance. -- I asked 3 times on reefcentral, and my threads get buried in no time! Might as well try here as well!

[WuHT]

Wow thanks for the quick and helpful advise.


The only reason im' not having dual corner overflows is that my stand does not exactly allow me to run piping across (the wood partitioning are load bearing , and i'm not sure if i want to bore holes through them

However i'm curious about how removing the teeth actually increases surface skimming (would make sense for the same linear length) -- >so what do you guys use to prevent snails and other things from going over the surface that you don't want to : ie can anyone link me to gutterguard'd or eggcrate'd teethless overflows :) ?

Unfortunately, I'm probably restricted to one overflow , so for 150 gallon aquariums it's advisable for a 1.25" bulkhead/drain pipe and go for a 1 inch return/bulkhead ... or go for the slightly smaller combo of 1" bulkhead/drain and 3/4" return/bulkhead

[Doug]

Wow thanks for the quick and helpful advise.


The only reason im' not having dual corner overflows is that my stand does not exactly allow me to run piping across (the wood partitioning are load bearing , and i'm not sure if i want to bore holes through them

However i'm curious about how removing the teeth actually increases surface skimming (would make sense for the same linear length) -- >so what do you guys use to prevent snails and other things from going over the surface that you don't want to : ie can anyone link me to gutterguard'd or eggcrate'd teethless overflows :) ?

Unfortunately, I'm probably restricted to one overflow , so for 150 gallon aquariums it's advisable for a 1.25" bulkhead/drain pipe and go for a 1 inch return/bulkhead ... or go for the slightly smaller combo of 1" bulkhead/drain and 3/4" return/bulkhead

Hope my last post was not to hard to read. The quote never worked proper for some reason. A single is fine then. You could use the sq. one as I mentioned or the angled corner type someone else mentioned. I have pics of both types if you wish to see them. My preference still would be whatever size hole it takes for a 1.5in drain but if not possible then a 1.25in. drain.

[mark]

WuHT not to turn your post into a how much flow to my sump thread but you mentioned 600gph. If that's what you want, then your on the edge of seems accepted a 1" inch bulkhead will gravity flow.

Before can say more, what type of tank you planning, what type of turn over and how much you planning on relying on your return pump for display turn over? One leaning is flow no more to the sump that the gph rating of the skimmer, I at one time had 2000gph going through my sump (since reduced to 1000gph).

Me, I'm on the side of go big. Just because you have a big hole doesn't mean you have to max it, but does allow for flexibility as plans change. Applies to return bulkheads as well as drains, Realize overkill but I have 2-2" drains on a 145g.