The Hole size in Overflow when using RD

[7thheaven]

Hi all~

I have plan to make new SPS tank. (90cm x 90 x 50 LxWxH)
1. Is it good choice if I use Red Dragon Pump 4.5 m3 for return?
I heard It is very effective (no noise,less electricity,very powerful)
and I am not thinking Closed Loop( I have 3 tunze 6100)
In my current tank, I use Iwaki 20RX (about 540gph)
I will connect chiller and my Ca reactor to RD
EX sump->RD->chiller->outlet (to main tank)
sump->RD->Ca reactor
Less electricity is very important factor in my country..


2. 1 is OK, How big is the hole in overflow needed? 1 inch is too small?
I am considering Dorso type.

Thanks in advance~

[keigo]

hi,

the 4.5m3 RD is how many litre per hours..??

cause I'm runing on 12m3 RD and I need a hole of at least 40mm but if the return is straight direct from RD.. I would advise bigger hole like 50mm for my case.. cause a direct return from RD is huge...

[7thheaven]

hi,

the 4.5m3 RD is how many litre per hours..??

...

Performance-Air/Water is 1189g/h

[keigo]

hmm 45kl/h huh... hmm then i would advise u to go for at least 2x50~60mm pipe to play safe and in case any pipe gatta jam...

[7thheaven]

hmm 45kl/h huh... hmm then i would advise u to go for at least 2x50~60mm pipe to play safe and in case any pipe gatta jam...

Thanks keigo....

two 50~60mm? Wow Too big~!!! :icon_redf

[keigo]

yes cause your is 45000l/h... it's a huge water vol move...
even when I run in 12000l/h my 1x40mm also just nice and 50mm will be good and prevent flood.. So you should know why you need 2x5-~60mm pipe...

[7thheaven]

Is it 45000l? 1189x3.75 = 4458l (about 4500)

Isn't it correct?

How can I calculate the water flow?

[keigo]

o sorry my mistake by having one more 0.. so it's 4500l/h only...
a very low water flow... then a 30mm pipe will be more then enough...

[keigo]

but why go for 4500l/h RD only.. after head loss you would be left with only max 3000l/h only.. and even worst with a tee off your main return will be somewhere less then 2000l/h

[7thheaven]

you think I need more big one?

I am thinking this one because it is better than Iwaki 20rx(it has a noise)
and effective...

and....

It is cheapest that any other RD models.....

[keigo]

cause your case will be a 3ft tank with 3ft wide...

so a 4500l/h RD pump is way too little...
you should consider at least 8000~10,000l/h RD pump...
if i'm not wrong a 8000l/h RD pump is out around 70or80 something watt only.. and still alot lesser then Iwaki

invest well on your return pump cause it will be one pump that help you move all your waste into your sump to be skim out by your skimmer...

and also to prevent future upgrading if you find the pump you have choosen flow are too little and when you want to upgrade you have to re-do your return pipe and overflow pipe which will kill you and may be impossible cause your glass hole is already been drill to that size only..

[Orion76]

Keigo, they have the metric system in Singapore don't they?

4.5m3 = 4500 l = 4500 KG

[Orion76]

RD's have a lot of headloss, that's the trade off for the low wattage, so keep that in mind when choosing a pump.

As far as LPH through the sump, I would not move a lot more water through your sump than the turn over rate of your skimmer, too much flow can give problems with bubbles getting into the tank.

[keigo]

RD's have a lot of headloss, that's the trade off for the low wattage, so keep that in mind when choosing a pump.

As far as LPH through the sump, I would not move a lot more water through your sump than the turn over rate of your skimmer, too much flow can give problems with bubbles getting into the tank.

well that depend on your setup right.... even with low flow the bubble from your skimmer output still will give you the same problem..

well my theory is.. let say u have 500l net water vol of tank.. and you got 7000l/h of return rate after head loss...

so are you going to confirm and tell me that for every 7000l/h of water going to your sump wont be the repeated and progress water and the 7000l/h of water going to your sump will be those old dirty water..

so with this mix of been process water and the old waster water in the main tank.. then percentage of getting those waste down to the sump for the skimmer to skim out is 50/50 or even less...

so that why explain why I will go for high flow with as much as 14times turn over rate for my tank... cause anything happen you can also get your waste water quickly go down to the sump and been skim out or filter out by sponge

[7thheaven]

Thanks...keigo and Orion76
so Which RD pump is proper my new tank spec? and wanna know hole size(in overflow).
just for return..
(90cm x 90 x 50) and my skimmer is schuran 150
and here is schuran150 spec
turnover approx. 1000/h,
air suction 350-400l/h


It is not easy to me...