Drilling 187G tank for coast2coast, final thoughts before diving in?

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#1
So I am going to be drilling a 187G tank for my next build and I was hoping to just get a little feedback from any flow and/or internal weir experts.

I have a 48” toothless external overflow from
Modular marine and my only doubt at the moment is where do I place the top of the weir. The design and intent was the hide the water line and this tank as you can see has a large thick center brace which makes a traditional toothed weir a non-starter if hiding the water line is the goal. So I did some math and with the 48” I was aiming for an 1/8” water rise at 10x turnover which should hide my water line and keep the water from submersing the center brace… ish.

so my last thoughts are, is the trim going to be enough headroom or do I have a potential for an overflow condition here? Of course only way that could happen is flow on and drains/overflow not working, but regardless of water level that’s a problem so just pretend here. When my return is off with this setup I would expect my water line to basically sit at the bottom edge of the trim depending on where I place the returns.

thoughts?

pics for reference
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All Delight

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#2
I have a coast 2 coast toothless overflow. I don't like it. Fish primarily wrasses always go over. I don't have snails (other than conch) cause they'll go over.
 
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I have a coast 2 coast toothless overflow. I don't like it. Fish primarily wrasses always go over. I don't have snails (other than conch) cause they'll go over.
interesting, is yours internal/external/built in? Have any pictures of the setup I could see?

with my current toothed overflow I really don’t see what the fuss is about, granted I only have 6 fish (1 of them being a wrasse) I can’t imagine how not having the teeth wild make any difference other than the water rise.

That being said however I am not overly concerned about fish going over, I’d much rather that than on the floor and this seems to be fish specific in most cases. I am also committed to the toothless for several reasons at this point so it’s going to happen but the real question is mounted at what height.
 
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So after stewing on it a bit I am thinking that I will mount the weir 1/8” below the trim allowing myself a full 1/4” of rise at full flow.

using the rectangular contracted weir equation if I can achieve a full 10x turnover (1800gph) and using my estimated 96” weir length I should see something like 7/32” of rise over the top edge. That coupled with the 1/8” drop below the trim should put my water line about 3/32” above the trim nicely hiding it and still allowing a little breathing room below the center brace.

I think I would be happy with the water just at the bottom edge honestly so even if I’m a little off here I think it will be okay. I just have to actually push some water!
 

Jimbo327

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#7
You are not giving yourself a lot of room for mistakes. Snails and other critters may plug your weir before it gets into your drains.

If you want to hide the water line, I rather lower the trim and give myself more room for errors.
 
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You are not giving yourself a lot of room for mistakes. Snails and other critters may plug your weir before it gets into your drains.

If you want to hide the water line, I rather lower the trim and give myself more room for errors.
I think it would take a lot of snails to plug the weir at 48” long haha. One big turbo could plug one of the 2” holes for the bulkhead but they wouldn’t fit into the weir to get in there anyhow.

plus I already started drilling it so game on
 

Jimbo327

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It’s probably more of my own paranoia. I know as soon as I try this, 5 small snails or worms are going to form a voltron and plug up that hole. LOL.

All that surface skimming would be nice.
 
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It’s probably more of my own paranoia. I know as soon as I try this, 5 small snails or worms are going to form a voltron and plug up that hole. LOL.

All that surface skimming would be nice.
haha I know what you are sayin, a snail Voltron I wouldn’t even be mad about honestly

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I went ahead and sent it though, the weir looks dangerously close to the top haha but we see what happens once I get some water in there I guess.

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I still have to drill the two returns, the glass is 7/16” thick so it took forever to get through. I’m going to finish the rest tomorrow
 

Jimbo327

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#11
The holes look good. Can't wait to see how close the waterline gets to the top.

I also want to hide the waterline, but I don't even have a canopy. I was thinking of just adding a metal brace to the top to hide the waterline. That will be very future project. But definitely want to see how yours look when you fill up the tank.
 
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If I did my math right then I should be good, I will definitely post up some pics once I get there. This was step one for this build, then I need to build a stand for it so I can move it into my house. I will prob start a build thread once the holes are done to track it.
 
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I left an 1/8” gap accross the entire weir below the trim so that should give me the space I need for 1000 gph without issue. The pic is misleading the gap is consistent lol but the trim isn’t.

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