# 1 or 1.5 inch Bean Animal? Flow rate question



## fesso clown (Nov 15, 2011)

I am having a new tank built. 80x20x20. (around 135 Gallons) I am trying to decide on the size of plumbing to put in the overflow.
1 inch full siphon will give me 1443.61 GPH should I really need to go to 1.5 inches as most people seem to do for a larger tank?
1.5 gives 3248.13 at full siphon at 18" head height... that seems a ridiculous amount of flow.


I am currently using an ehiem 1262 ( 898 GPH ) with 1 inch full siphon on a 60(ish)Gallon tank. I close the line to match the pump and I divert some water to my fuge.

My Avast CS1 Skimmer is fed by a MJ1200(300 GPH)
Does that mean I can only process 300GPH and I should keep the flow rate through the sump around 300-400GPH?

Something tells me that 1 inch lines will be sufficient but I want to check my thinking. I would like to keep the 1 inch for a lower profile overflow box.

Thoughts please?


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## advanced reef aquatics (Apr 20, 2009)

1.5" for sure.


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## fesso clown (Nov 15, 2011)

advanced reef aquatics said:


> 1.5" for sure.


Thanks Flavio, I am not sure I understand why. Can you explain please.


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## Bayinaung (Feb 24, 2012)

the bigger the pipe the more flow rate you can have from the overflow? if you want less adjust the return pump to the desired flow rate?


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## advanced reef aquatics (Apr 20, 2009)

sorry as i had to go when i started writing, your room for error is far less on 1.5" vs 1.0"
simple things such as snails clogging a pipe to debris accumulation.
im sure 1.0" will suit your needs, but i prefer a larger diameter.
also as stated you can always reduce flow on 1.5" to suit your needs, where as 1.0" your limited.


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## deeznutz (Aug 21, 2013)

My last tank I ran 2 x1.5" drains. It was great, but like you said the profile of the over flow is at least 6".

3 x 1" drains is more then enough. You should only run your skimmers rate through the sump. I bit more is fine, but in no way will you be maxing out the 3 x 1" drains. PLus add strainers to you drains except the emergency. make sure to check them periodically and have them cleaned semi annually.

-dan


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## PaulF757 (Dec 9, 2013)

I'm using 1.5" on my 180G, with a gate valve, adjusting flow rate is a piece of cake.


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## ameekplec. (May 1, 2008)

advanced reef aquatics said:


> sorry as i had to go when i started writing, your room for error is far less on 1.5" vs 1.0"
> simple things such as snails clogging a pipe to debris accumulation.
> im sure 1.0" will suit your needs, but i prefer a larger diameter.
> also as stated you can always reduce flow on 1.5" to suit your needs, where as 1.0" your limited.


But if you have the same flow rate, aren't you going to just close the 1.5" pipe to the same opening at the valve as the 1" pipe, hence negating any benefit of having larger plumbing? Also, having capacity to increase flow by 600GPH over the 1262 (assuming no loss due to elbows and the like), it's still a lot of "space" to work with.

FWIW, I'm pretty sure I'm running 1" plumbing on my system (100G display w/herbie return).

Unless you're intending to have a really high return rate, I think you're fine with the 1". Also, I've never had a snail crawl up and out of the water into the overflow box, let alone get stuck on the drain, so IMO, it's not a real concern. Additionally, given the design of the bean animal (or herbie), the additional full siphon emergency drain will handle any blockage should it occur.


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## fesso clown (Nov 15, 2011)

After reading through(again, it's been a few years) the epic Bean Animal thread on RC it turns out the reason he uses 1.5" (on 1 inch bulkheads) plumbing is so that the open channel is more quiet and has nothing to do with flow or blockage. I have been running my Bean animal the wrong way for 1.5 years....works just fine... I keep my open channel completely dry as well as the emergency. The only time either gets wet is if a snail manages to block my main siphon(it has happened). 

So that being said, I am only going to run 1 inch bulkheads with 1 inch pvc. 

Thanks for the replies.


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