Adding holes

dallasg

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hi hennie and all :)

this is what i am planning to do, but want to check i am not drilling in the wrong place.

these are all new holes
144249990f248af11.jpg
 

dallasg

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bump
 

viper357

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Just don't drill the holes too close to the edge of the glass or you run the risk of cracking the pane.
 

dallasg

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about 10-15cm from the edge
 

viper357

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That's fine.

In the pic on the right, what are the 2 holes in the centre right?
 

dallasg

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overflow holes, for durso pipes
 

viper357

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How many return lines will you be having? Where will they be placed and in what direction will they be pushing flow?
 

dallasg

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there are already 2 holes in the back pane of the tank, a 25mm and 40mm, i want to use those for sump and refugium returns and drill new ones at the bottom for cls and overflows.

each tank also has 3 5000Lph sun sun pumps

the cls each tank a 10000L external and for returns to both a 18600L pump. they will share a common sump etc
 

viper357

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If the return holes are close to the edge of the tank and depending on the placement of the sunsun pumps, I would perhaps move the bottom cls holes slightly inwards a bit more. The return lines will create enough flow on the outer edges of the tank so by moving the cls lines inwards a bit more it will help with extra flow towards the centre of the tank.

The main idea of having a cls is to maximize the amount of flow coverage in the tank, thereby eliminating any dead spots. The placement of the cls holes will mostly depend on the placement of your additional internal pumps. If you try and work out which internal pump will be pushing where and thereafter work out where to place your cls outlets, should result in a winning combination.
 

dallasg

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cool, i will move them more centrally
trying to get as much turbulent water movement.
i will make them about 20cm eighter side of the overflows
 

viper357

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i will make them about 20cm eighter side of the overflows
That might be a bit too much, but of course it all depends on which direction they will be pointing. I was thinking more sort of halfway between the edge of the tank and the overflow.
 

dallasg

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That might be a bit too much, but of course it all depends on which direction they will be pointing. I was thinking more sort of halfway between the edge of the tank and the overflow.
even better idea :) thanks

this wont weaken the base to much?

i will place a piece of glass between the bulkheads and tank for strength if its needed
 

viper357

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this wont weaken the base to much?
I doubt it, I've seen tanks with about 6-8 holes drilled in their base and the back pane for a cls, but best to get a tank builders opinion on that, or ask Oom Hennie. ;)
 

dallasg

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cool, also waiting for leslie to reply
 

leslie hempel

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is there any reason why you want to go 20mm on some of the holes? i suggest 32 as a minimum (exiting but i see you have 50mm and 25mm return) as when you add fitting you reduce your ID,s.. its safer to go bigger as a rule.. a 20mm hole with a fitting in it will be roughly 15mm inner diameter reducing flow and ading significant back pressure on a biggish pump..

as for the positioning i have gone as much as 5cm from the edge of the base pane of glass with 32mm holes in 10mm this is generally safe but the tank heights have never exceeded .700mm (just thought you should know)

other than that all looks fine...
 

leslie hempel

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height of proposed tank and size of proposed CLS pump will be important things to consider here can you provide us with specs of those 2 items?
 

dallasg

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thanks Les,

the tallest tank is 600mm, but the overflow is to low

using a 20mm and 50mm coz i only have those hole saws
 

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