Overflow rate for dual overflow 120

[yellowtruck75]

I am in the process of setting up my new Perfecto 120 tank with dual corner overflows . Any idea what the overflow rates would be for the tank? I am putting my sump in the basement directly below the tank and need an idea of a return pump from the sump. Also should I plumb both overflows together before the sump or have them dump in separately ?


THANKS

 

[LobsterOfJustice]

If they are 1" you will probably get about 600-700 GPH through each. Drain them separately.

 

[yellowtruck75]

So I might be looking at 1200 to 1400 gallons per hour. Would a Sequence Dart work?

 

[Hop]

Um... No. Not unless you throttled it back 70%

If you keep the 3-5 times the system volume through the sump per hour theory then you only want about 500gph through both drains.

 

[Playa-1]

Your looking for around 500 gph (give or take a little) through the sump. The rest of your circulation coming from power heads or a closed loop system.
Even though the dual skimmer/overflows may handle up to 1200 gph, if you try to put all that through the sump then your very likely to not be happy with micro bubbles and drain noise. It's just not necessary and you can get a smaller, quieter, and more energy efficient water pump. Look into a nice Ehiem 1260 or 1262 and see if that doesn't suit your fancy
It's usually suggested to start with around 3 to 5 times your tank volume through the sump. You can use the headloss calculator on the main page and plug in your specific information and it will give you a good idea of what size pump you need for the return pump.

 

[LobsterOfJustice]

I've always shot for about 10x through the sump.

 

[yellowtruck75]

I have a Mag 18 on my 125 now so maybe I will use that agian.

 

[Hop]

What is the flow-through rate of you skimmer? Probably 1-3 times the system volume per hour. So a mag 18 is about 10 times more flow per hour than your skimmer. Which means you have to pass water through your sump 3 times to get the water as clean as it would be with less flow through. In essence, if the sump is truly to hide equipment, remove DOCs and aid in filtration, then upping the flow that high is really a waste of electricity.

 

[poppin_fresh]

Because your sump will be in the basement, I dont know if a Mag 18 will have enough flow with that much head. I am using a Gen X Mak 4 for my basement sump along with a Rubbermaid 100 gallon stock tank. I estimate the Mak 4 would move about 750 gallons/hr if I sent it all up to the display, but i dont.

HOP is right that you ideally want to match the sump turnover with the skimmers capacity. I have my overflow plumbed into my skimmer, thereby getting maximum skimming effectiveness. This only works if the overflows and skimmer are matched closely.

You should do some measuring and planning and then run your plumbing through the head loss calc on the main page of RC. This will tell you what kind of flow the mag will have pushing water up from the basement.

 

[Hop]

Guess I should have read the sump in the basement part:lol:

Sorry, working on finals today has wiped my brain out and I think I'm gonna stop posting tonight

 

[poppin_fresh]

I'll let it slide....this time! :thumbsup:

 

[LobsterOfJustice]

If you have your heaters in the sump, I'm not even sure three times is enough to keep your tank up to temp.

 

[Hop]

It's plenty to keep the temp up. Been running that way for seven years with 2.7-3.5 times turnover

 

[Playa-1]

OOOPss!!
I missed the basement part too
I still like the lower flow through the sump, but i realize its a controversial subject open for debate...

 

[Hop]

<a href=showthread.php?s=&postid=11067103#post11067103 target=_blank>Originally posted</a> by Playa-1
OOOPss!!
I missed the basement part too
I still like the lower flow through the sump, but i realize its a controversial subject open for debate...

Your right! I forgot that it was the topic that made me take a few month hiatus away from reef central:lol: And here I am posting about it again:lol: Maybe I should go do some woo-saaa stuff

 

[yellowtruck75]

I have never thought of running the overflows through the skimmer. I am running an MRC 2 skimmer and don't know if the dual overflows into the basement will be enough to power the skimmer.

 

[LobsterOfJustice]

Becketts require high pressure pumps to drive them, so you'd be better off not feeding it directly. Chances are you have a pretty large pump powering it (you should). So if you're trying to match the two flows, you are probably going to end up with at least 5x. I have a GenX PCX-70 on my skimmer, which means i'f I'm trying to match my sump flow with my skimmer flow I want about 1500 GPH through my sump or 16x turnover for me. I just took the given GPH value for that pump, I know realistically it is going to be less because of backpressure (especially from the injector).

Hop, don't worry, I'm not trying to argue. I think basically what it comes down to is that it doesnt matter.