Drain size/ flow?

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lilredwuck

Guest
I am wanting to drill my tank soon. 125 with a 55 sump. I have every size hole saw available. I have a corner overflow if I want to reinstall it, but I don't. I like the horizontal ones up top.
Question is, what size should I drill, and how many. Also how many linear inches should I have for skimming? (What size I should make the overflow) Should I go with one overflow or two. I have braces on my tank, so I can only put it in 2 places.

 
2quills

2quills

Well-Known Member
I trust you know that you need diamond coated holesaw bits to get the job done?
I drilled my 120G for two 1.5" bulkheads. I'd say go with either two 1.5" or two 2" bulkheads.
I haven't made my overflows yet but there will be two of them 8" long by 3" deep = 28 linear inches total. I've shared emails with Marc Levenson from Melevs Reef who builds custom overflows and he told me that 28" for my tank would be plenty. For reference he has a 280G tank with a total of 36" linear inches of overflow (skimming area). Hope that helps.
 
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lilredwuck

Guest
So each 1 1/2" drain will drain anywhere from 700-950 gph gravity fed. How much flow am I looking for to go through the sump? This will also help with my pump choices.
 
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lilredwuck

Guest
Looking at getting a Reef Octopus 200, heaters, top off etc.
 
2quills

2quills

Well-Known Member
There shouldn't be any need to have more than 5x the turnover rate of your tank going through your sump per hour. So 600-650GPH is more than enough IMO. One 1-1/2" drain is more than cabable of giving you what you need...the second one is more of a fail safe. Pluss with the two drains that should mean that your system will drain quieter...less air getting choked off within the drain lines means less gurgling noises. I'd maybe look into something like an Eheim 1262, or a Mag 9.5 pump. Something along those lines for pump sizes. JMO
 
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lilredwuck

Guest
ok, so that all that is figured out, How big should I make my overflow?
 
al&burke

al&burke

Active Member
I have a question about the size of the teeth on the internal overflow (sorry i don't mean to jump into your post) - how deep should they be in repect to the black plastic trim on your tank in order to ensure that the water line is not below the tank trim.
 
bang guy

bang guy

Moderator
You won't like my answer probably. I would start with 1/2" and then you'll have to drill further if the water level is too high.
I say that because you can drill further but it's difficult to undrill it if you go too far.
I'm questioning if five 1/4" slots is sufficient.
 
al&burke

al&burke

Active Member
The drawing is just the end view, i was thinking 1/2" at least. The overflow box will 8" x 3" going with what 2Quils said for the 120 gallon tank. I am making this for a 65 gallon tank. I will have 2 1" drains - one as the main and the second as a back-up, Thanks Bang Guy.
 
2quills

2quills

Well-Known Member
Quote:
Originally Posted by Al&Burke http:///forum/thread/381259/drain-size-flow#post_3320499
The drawing is just the end view, i was thinking 1/2" at least. The overflow box will 8" x 3" going with what 2Quils said for the 120 gallon tank. I am making this for a 65 gallon tank. I will have 2 1" drains - one as the main and the second as a back-up, Thanks Bang Guy.
The first time I had emailed Marc I was inquiring about the overflows that he makes...he makes his overflows with 3/4" spacing between teeth I believe. I'd emailed glasscages about their overflows as well but they told me they don't make them with 3/4" spacing. Thiers are made with 1/4". I tried to tell him that I was looking for 3/4" spacing and the guy seemed to get irritated because I didn't want his 1/4" spacing...so I never emailed him back.
Edit...I looked up my old email...Mark makes his with 1/4" spacing between 3/4" teeth - 1" deep. I was looking for 3/4" teeth from glasscages and they didn't seem to want to make them that way for me.
 
acrylic51

acrylic51

Active Member
I would go with 1/2" slots/teeth.....1/4" really isn't a whole lot IMO......Corey GlassCages does sloppy work acrylic wise......
 
acrylic51

acrylic51

Active Member
I would cut the overflow teeth to just a hair below the trim of the tank......That way once the pump is fired it rises just a bit, and then starts rolling into the overflow...It still leaves you a little wiggle room inside the tank to make any adjustments with the pump as well.....With the teeth being cut below the trim line as shown; IMHO your water level will be below the black trim on the tank when the pump is running......
Quote:
Originally Posted by Al&Burke http:///forum/thread/381259/drain-size-flow#post_3320376
I have a question about the size of the teeth on the internal overflow (sorry i don't mean to jump into your post) - how deep should they be in repect to the black plastic trim on your tank in order to ensure that the water line is not below the tank trim.
 
acrylic51

acrylic51

Active Member
Tom is a "different breed"
Actually in person he's a pleasure to talk with and so is his wife....Tom just doesn't like being told his business basically......When I dealt with him on several custom tanks, I laid out detail plans of what I wanted and expected, and drew it all out and faxed the plans over to him.....I told him to critique the plans and note his changes, what he could/couldn't or wouldn't do and fax them back.....Worked perfect all 4 times that way......that way they had a detailed layout plan in front of them when building, all the measurements etc....And when I picked the tanks up I had a copy of the plans they worked from and I would take a tape measure and measure every last hole......

Quote:
Originally Posted by 2Quills http:///forum/thread/381259/drain-size-flow#post_3320515
Yeah, I wasn't impressed with customer service either lol.
 
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lilredwuck

Guest
Back to me now. If I am running 600 gph the reefcentral calculator says I would need a minimum of 9 linear inches, and a drain size of 1.01"
Still going to go with two 1 1/2" drains though. Probably in just one overflow. Seeing what I have in stock, we'll see how long I'll make it. I know the bigger the slower the flow over it, means less noise.
 
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