Modular Marine Overflow Selection Help

[Caseyz]

All,

Does anyone have experience with the Modular Marine overflows? I am in the process of designing a 210 display from CD Aquariums and I am trying to select the correct overflow. I am attaching the options list from the CD website. I looked at the MM website and they rate the overflows in GPH but they don't give the dimensions. The CD website just gives the dimensions with no GPH. I am looking at a total flow rate of ~2400 GPH and need to know which option to chose.

Any help is appreciated.

 

[Caseyz]

For reference I think this is the one that I need. 3000 GPH should be enough overhead for my 2400 GPH flow.

https://modularmarine.com/collectio...-low-profile-overflow-box-with-removable-weir

 

[((FORDTECH))]

For reference I think this is the one that I need. 3000 GPH should be enough overhead for my 2400 GPH flow.

https://modularmarine.com/collectio...-low-profile-overflow-box-with-removable-weir

I will venture to say that even tho it’s rated at 3000 you will have hard time to flow 2400gph. This is a ton of water !!!! That much water flowing thru a sump is also crazy fast makes tuning a skimmer close to impossible. I have a 300 gallon tank with a custom modular marine overflow. Had it built 48” inside tank and 36” outside box. I have 3 of the 1 1/2 “ drains and 2 additional 1” drains to feed my algae scrubber. I use 2 cor-20 pumps and I thought I was gunna run 2,000gph (1000 from each) also but after said and done it was like roaring rapids thru my 75 gallon sump. Splashing all over and for 3 weeks skimmer just over flowed. Till I turned it down to 1000 gph (500gph each) now it works nice. I love the overflow I’m very happy I went with it even tho I was unrealistic on the flow thru it . Slow That flow down and add more power heads. IMO Good luck with this.

 

[Caseyz]

I will venture to say that even tho it’s rated at 3000 you will have hard time to flow 2400gph. This is a ton of water !!!! That much water flowing thru a sump is also crazy fast makes tuning a skimmer close to impossible. I have a 300 gallon tank with a custom modular marine overflow. Had it built 48” inside tank and 36” outside box. I have 3 of the 1 1/2 “ drains and 2 additional 1” drains to feed my algae scrubber. I use 2 cor-20 pumps and I thought I was gunna run 2,000gph (1000 from each) also but after said and done it was like roaring rapids thru my 75 gallon sump. Splashing all over and for 3 weeks skimmer just over flowed. Till I turned it down to 1000 gph (500gph each) now it works nice. I love the overflow I’m very happy I went with it even tho I was unrealistic on the flow thru it . Slow That flow down and add more power heads. IMO Good luck with this.

Thank you for the input. I had planned on using the Triton method which calls for 10x the display each hour hence the 2400GPH number. The sump I am planning on is ~60G and at 2400GPH that would be 40G per min through the sump. I take your point that this is a lot of water to be moving. Guess I will just have to tune it and see what it will do. I had planned on using the Bean Animal design with 1.5" returns.

 

[Gablami]

Aren’t the dimensions on that page?

 

[Gablami]

i don’t understand how tank turnover is supposed to decrease ones ability to tune the skimmer. If you’re using an internal skimmer in a sump compartment whose water height does not fluctuate, there should be no issues.

That said, I agree that trying to get 2400gph flow is unrealistic through 1.5” pvc. The estimated amount of gravity fed flow through a 1.5” pvc is 2100 gph. So if you want 2400, you would need to deviate from the “bean animal” and have the second drain pipe also restricted and the third as a trickle.

My opinion is you won’t find many large tanks running triton method who attempt to get 10x tank turnover. It’s unrealistic and unnecessary.

 

[Caseyz]

Aren’t the dimensions on that page?

Yup, found them via Google after I posted. Their website is a little tough to navigate. Or I am obtuse with is equally likely. ;)

 

[Variant]

I got modular marine overflows on 3 separate occasions. Each time I wish I got 1 oe 2 sizes above my return pump capability.

I would honestly slash the ratings on the overflows by 25-50%.

Great deaign but a bit overzealous in its ratings in my opinion.

 

[ca1ore]

I agree .... I wanted 1,800 gph on my 450 so I bought the 3,600 gph 36” version.

 

[Blue Ring Octopus]

If you are buying a CD tank they should be able to recommend the correct overflow and install if for you.