Overflow box question

[Schplitter]

My tank is 17" tall. I will be running 2 mag 12s and the returns will be 2 1.5 inch dursos.

How tall should the overflow box be?

I was thinking 1.5 inches below the top of the tank = 15.5"

BK

 

[sirreal63]

If I may ask...why two Mag 12's? That is a horrid pump. It is the same as adding a 220 watt heater to your tank turned on all the time. That is a lot of flow through the sump when there isn't much need for that kind of water movement...it serves no purpose does it?

Each one of those pumps pulls 110 watts with no load on them...so if you add the head and loss from elbows then the wattage draw increases...all for having lots of flow though the sump. It makes little sense. Take a few minutes and read this thread...it does make sense I can tell you I saw increases in my skimmer performance and less heat when I slowed down my return through the sump.
http://www.reefcentral.com/forums/showthread.php?s=&threadid=550482


Use lower wattage powerheads for tank movement...MjMods, Koralia's, Seio's or Tunze's are a much better choice for water movement in the display. If you want to run an OM or eductors do it on a closed loop not through the return pump.

 

[latazyo]

if he's anything like me he doesnt want huge pumps in his display

you just need to measure it with a tape measure and see

you dont want it to be too low, that really sucks

and honestly, if you have it too high and you're afraid of overflowing...well if its going to overflow .5" its going to overflow 1.5" so what's the difference?

 

[JxMetal]

but if he's not going to have a stand-alone fuge, it almost defeats the purpose of having a fuge. With that much water movement in the fuge, there's not enough time to break down nitrates and such.

 

[Im Lon 2]

I don't know about how tall but make sure you have 18" of water surface per 1200 GPH. Even though that pump will be more like 900-1000 GPH by time it gets to the tank due to head pressure.

I didn't think about that on my 180, and I cannot turn my pump up all the way with out mod-ing my overflow.

Using the following input parameters
Gallons per Hour = 1200

Drain and Overflow sizes are calculated as
Recommended minimum drain pipe diameter = 1.43 inches
Recommended minimum linear overflow size = 18 inches

 

[Schplitter]

Good point guys.

I want the 2 pumps just in case one decides to die or I have to run a generator....

The other reason I want to go with a 2nd mag 12 is because I have one on my current tank and I hate having 2 different pumps. Just looks bad.

I know the darn things get hot and do add a lot of heat to the sytem but even with my 75 gallon tank (75gal total volume) the mag 12 is only adding 1.2F to my system. The new system will be about 140 gallons.

I was planning on having a seperate chamber for the 2nd pump just to have it submerged. Reduces the noise and heat.

The sump is going to be 67" long 13" wide and 16" tall. Even if I were to use both pumps as returns I don't think that I would have too much flow....

latazyo is correct. I hate the look of powerheads in the front, back anywhere in the display. If everything does go according to plan I will have no pumps and other things in the display. I was planning on jets all across the top of the tank pointing all over the place. Something like lockline but home made.

Thank you,

BK

 

[Schplitter]

Lon,

the plan was to have a 6" front to back and 12" wide overflowbox in the tank. So that gives me 24". With 2 of the pumps running I should increase that to 33".

If I wanted to play it safe I would have to make the box something like 5" deep and 25" wide. That would look bad and would reduce the size of the tank.

I think the 2nd mag 12 might have to go onto a closed loop.

Anyone else have any ideas?

BK

 

[sirreal63]

Why not use an Eheim 1260 instead?

If you are only going to keep softies and low flow creatures then your plan will be fine. It won't be enough flow for SPS and you'll end up with powerheads if you want SPS.

Something to consider...the most nutrient ladden water is at the surface of the display...your overflow takes that water to the sump where it is processed and returned to the display. The longer that water is in the sump the more of it is processed and more nutrients removed. By sending it so fast through the sump you are not processing it, you are mixing those nutrients back into the water of the display. You have the added issue of noise from the overflow and heat from the pumps. If you run a smaller return pump the water gets processed longer. I keep a small powerhead in the sump to get the chaeto the flow it likes. Use a closed loop for additional flow in the display which also cuts down on heat.

There are many ways to set up a system and this one has been gaining in popularity for a few years now. I would never go back to a fast water movement through the sump...it just makes sense not to. My skimmer works better and my chaeto grows great and my entire system runs off a single 30 amp breaker, everything, heater, pumps, powerheads, lights, reactors, fans, skimmer...everything. My tank stays between 78 and 80 degrees, I keep my place at 78 degrees and a fan on the tank.

It simply works and is dead quiet and efficient.

 

[Im Lon 2]

If I didn't have Teeth on the overflows it would work just fine.

Do you plan on having teeth or smooth overflow?

 

[Schplitter]

sirreal63: i plan on keeping only a few easy to keep sps and all other will be softies and LPS. I will definetly have to go witha closed loop instead of the mega flow through the sump...

Lon, no teeth on the overflow and then maybe some eggcratge to stop the fish from riding the pipes...

 

[sirreal63]

It is just something to think about. Conventional wisdom has always been lots of flow through the sump but at one time bio-balls were the conventional wisdom.

No teeth on the overflow and eggcrate is a good plan.

 

[Im Lon 2]

<a href=showthread.php?s=&postid=9991296#post9991296 target=_blank>Originally posted</a> by sirreal63
No teeth on the overflow and eggcrate is a good plan.

Yes, very good idea

 

[JxMetal]

I don't understand the no teeth thing....

 

[Schplitter]

The teeth block water flow and if you go over them they crate bubbles. The water is turbulent and therefore makes lots of noise.

 

[latazyo]

Im assuming we're talking glass overflows, in which case it would be ridiculously difficult to cut teeth

that's what we're talking about metal

 

[Schplitter]

Yup, glass.

What's the best way to hide the pipes in the overflow? I was thinking some black acrylic on the inside of the overflow box?

 

[Im Lon 2]

get with stupid he might have some black PVC left that is 1/4" think. That is what he just put on his tank and used some silicone to hold it in place. Looks good I think.. I wish he post some more pics..

 

[latazyo]

schplitter,

if you can safely paint PVC with krylon and submerge it, then Im also assuming you can paint the glass with it and submerge that

 

[Schplitter]

is that a brand of paint or?