Help determine flow for overflow hole

[Jake_the_reefer]

So I plan on drilling a hole in the top center of my 60g cube for an overflow into a 30g sump and I am looking to pump the water back into the tank at around 450-550 gph but I am unsure how big of a hole I should drill into the tank to achieve this. I've never drilled a tank out or used a sump so I am unsure how big of a hole i should do or how many inches from the rim i should drill.

 

[KrisReef]

Figure out what pump you will use and size the hole to the pump plumbing.
I believe a 1" hole is more than enough for that much flow, to more directly answer your question.

 

[GThompson]

What do you plan on putting in the hole for the water to run through?

 

[GThompson]

Figure out what pump you will use and size the hole to the pump plumbing.
I believe a 1" hole is more than enough for that much flow, to more directly answer your question.

Would he be better off to put a 1 1/2” hole and then he could always slow the flow down with a gate valve ?

 

[Jake_the_reefer]

What do you plan on putting in the hole for the water to run through?

I would think something like this but I'm not too sure
Or just a bulkhead strainer

I would like a bulkhead overflow box.

 

[GThompson]

I would think something like this but I'm not too sure
Or just a bulkhead strainer

I would like a bulkhead overflow box.

I purchased the Synergy shadow 16 and the bit to drill the glass. Really nice looking overflow. Good luck with it

 

[RJinPV]

You need to determine what bulkhead fitting fitting you are going to use. The overflow on my 55 Gallon is a 1" PVC pipe. That is the inner diameter. The OD of the pipe is actually ~1.3". The fitting it slips into is actually bigger and the hole in my tank for the bulkhead fitting is closer to 1.75". So a 1" ID pipe should be adequate for the flow. That bulkhead fitting inlet screen you selected should work fine.

 

[KrisReef]

Figure out what pump you will use and size the hole to the pump plumbing.
I believe a 1" hole is more than enough for that much flow, to more directly answer your question.

Never mind, I had your flow going the wrong way. :) Sorry about that.

 

[Jake_the_reefer]

You need to determine what bulkhead fitting fitting you are going to use. The overflow on my 55 Gallon is a 1" PVC pipe. That is the inner diameter. The OD of the pipe is actually ~1.3". The fitting it slips into is actually bigger and the hole in my tank for the bulkhead fitting is closer to 1.75". So a 1" ID pipe should be adequate for the flow. That bulkhead fitting inlet screen you selected should work fine.

Would the inlet screen I selected allow for surface skimming if I placed it in the right spot or am I limiting myself on skimming if I dont use an overflow box

 

[KrisReef]

Surface skimmers are very nice because they are more forgiving for fouling organisms, but a single can work fine, especially in a lightly stocked display. Gl

 

[SmedenS]

Hi I am in similar situation planning a new tank and trying to decide on pipe sizing, flow etc.

I am going to try this coam outlet from the Koi market. 16 USD.
https://www.lazada.co.th/-i272205850-s429755012.html?urlFlag=true&mp=1

I bought it as it is small and discrete, but still holds a 35cm "coam" and in theory allowing more surface skimming than an outlet with less coam length?

Pipe inner dia is 27mm, but needs a bit of DIY with glue and drilling the screwed centre from 21 to 24mm.

 

[Taxus812]

I found this chart that may help

https://www.hy-techroofdrains.com/water-flow-through-a-pipe

 

[Even Further]

So I plan on drilling a hole in the top center of my 60g cube for an overflow into a 30g sump and I am looking to pump the water back into the tank at around 450-550 gph but I am unsure how big of a hole I should drill into the tank to achieve this. I've never drilled a tank out or used a sump so I am unsure how big of a hole i should do or how many inches from the rim i should drill.

I would purchase a Modular Marine overflow kit and install per instructions. You're better off with two smaller holes than one big one. The bigger the hole the further away it should be from the glass panel edge. Common practice is 1 to 1.5 times the holes diameter from the edge to hole.

 

[Even Further]

Hi I am in similar situation planning a new tank and trying to decide on pipe sizing, flow etc.

I am going to try this coam outlet from the Koi market. 16 USD.
https://www.lazada.co.th/-i272205850-s429755012.html?urlFlag=true&mp=1

I bought it as it is small and discrete, but still holds a 35cm "coam" and in theory allowing more surface skimming than an outlet with less coam length?

Pipe inner dia is 27mm, but needs a bit of DIY with glue and drilling the screwed centre from 21 to 24mm.

That thing will be create a vortex since it pulls water too close to the surface. You'll end up with gurgling, surging, slurping noises from that thing.

 

[SmedenS]

That thing will be create a vortex since it pulls water too close to the surface. You'll end up with gurgling, surging, slurping noises from that thing.

Thanks for the warning.
After further considerations I will try to get something similar to the overflow from Modular Marine.