Sizing of Baffles in Sump!!!

SteveNMegz · #1 01/07/2008, 10:01 PM

Hey Guys,

We need to try and figure out exactly how high the baffles need to be in our sump(no clue what determines this). Its a 65 gallon display, 30 gallon sump, 300 GPH overflow and haven't purchased but probably going to get a mag 5 pump.

How do you guys determine the height?

Thanks for all your help!!!

dc_909 · #2 01/07/2008, 10:24 PM

You can check out mine below. Basically your sump needs to be able to handle the water from your tank if your electricity goes out. The higher the returns are in your tank, the higher they can be.

My returns are right at the top and my water level in sump is at the point in which it can handle all the water from the tank when power is out.

The skimmer baffles need to allow enough water for your skimmer to run correctly.

120 tank with 50 sump

d.french · #3 01/07/2008, 11:07 PM

my sump on my 75 gallon is 32L x 12w x 20H and i run water level at 8" deep for my skimmer to run correctly, i have a euro reef cs5-3 skimmer overall height is 25". i was told 6-8 inches for skimmer area but have seen some 10" deep. plus with my utube style overflow during a power loss my sump will hold xtra water from display until overflow stops and automatically restart when power comes on.

d.french · #4 01/07/2008, 11:15 PM

i run through skimmer area, than refugium area, than return.

FranktheTankTx · #5 01/07/2008, 11:57 PM

This is pretty simple. If I knew your sump design. Let's say you were doing a skimmer/return/fuge design.

What height maximum does your skimmer require if you use an in sump skimmer? For example, most are 8-9". Make the first baffle that height. Then the next baffle would be a hanging baffle so that water travels under it. You would hang it about 1.5" above the bottom and it can be any height reall as long as it's taller than the first baffle. 10-12" is fine. The next baffle should be the same as your first baffle, and this will be the last baffle between the skimmer and return.

Next, the fuge. From left to right we have done 3 baffles thus far. Usually people make the fuge a little taller, say 12-14" This way you can have a 4-6" sand bed and still have 6-8" of water volume.

Now, if you don't plan to do this set up then I did this all for nothing. Anyways, I hope it helps you get the point.

SteveNMegz · #6 01/08/2008, 12:54 PM

very helpful, we're not goign to be putting a fuge in this tank just strictly a sump then later we'll add a fuge in a seperate 10 gallon, So I think my skimmer doea measure at 8" in sump, so I will make the first baffle 8 inches high and carry on from there, right?

Thanks for helping us out again everyone, we wouldn't have figured it out without you!

SteveNMegz · #7 01/08/2008, 05:03 PM

now whats the difference between having the baffles with water flowing over either end and the middle one higher, or havin the ends higher and the middle against the bottom???

FranktheTankTx · #8 01/08/2008, 05:10 PM

The reason I like the middle baffle hanging is because this allows water to move along the surface. This stops that skim ontop of the water. Your first baffle is 8" high to set the water level. Then your 2nd baffle hangs to catch the bubbles from the intake and skimmer. And if a 3rd baffle was not used then water would enter from the bottom and the surface would never agitate with out the help of a ph (another piece of equipment). So you add the third baffle and the water flows over the top to agitate the surface. Make sense?

SteveNMegz · #9 01/08/2008, 06:56 PM

so if I set it up so the middle baffle is "hanging" where will we see our water evaporating from? would it be the return pump section???

SteveNMegz · #10 01/09/2008, 10:01 PM

????

siwelk · #11 01/09/2008, 10:03 PM

i believe most of the evap occurs in the return section due to the heat mostly. the majority of ATOs i have seen keep the float switches in the return section of the sump because it fluctuates the most.

HTH

dsn112 · #12 01/09/2008, 10:11 PM

evap will be in the return for sure.

CHASDB · #13 01/09/2008, 10:13 PM

Yes, the return pump section will be where you see the effects of evaporation and where you would locate the sensor for your ATO. Have you seen Melve's reef site, lots of info on building acrylic sumps and sizing/layout. Are you using a glass tank as a sump? I have read of folks with problems if they use kitchen/ bath silicone with the anti-microbial additive in the silicone, just read the tube.

SteveNMegz · #14 01/09/2008, 10:13 PM

we were told that if the outer baffles were higher (middle against the bottom) then evap. would take place in the return section, does it make a difference?

are there any positives to having the outer baffles higher than the middle???

FranktheTankTx · #15 01/09/2008, 10:21 PM

Steve & Megz

Oh no, make no mistake about it... the evaporation will take place in the return section. Water is constantly entering the intake (skimmer) section... evaporation cannot happen here. It just won't. Don't ask me how because it baffles the hell out of me sometimes. I start to understand it and then I try to think logically about it and I'm baffled all over again.

All I can tell you is trust me 100% of the time the evap occurs in the return section. Water will enter the intake flow over the first baffle, under the next (bubble trap) and over the third and into the return section. This is where an ATO (automatic top off) will keep the level constant when evap occurs.

spleen93 · #16 01/10/2008, 02:19 AM

Evaporation will take place at any point in your tank where there's an air/water boundary. It'll just show up in your return section of your sump since that's the lowest part of the water system and the baffles and the overflow maintain water level in all other compartments in the system. So yes, Frank is right - keeping the ATO sensors in the return section is the right move.

Spleen