Overflow box question

[Randrew215]

My 125 gal build thread is coming soon, but I have a question in the meantime:

My internal overflow box allows for 3/4" between the tank top and where the water level sits. This is dictated by the design of the overflow box itself, so I could change it but it would be a little bit of work to do. I'm worried that 3/4" isn't enough extra space and that transient wave made by my powerheads will exceed this height. On the other hand, I don't really want to drop the water level down an extra 2" to accommodate potential waves. Have other people encountered this problem and how did you choose to deal with it? Thanks!
-Andy

 

[SkiFletch]

So let me get this straight, it's 3/4 of an inch WITH the return pump running? If so, that should be enough clearance. If its 3/4 of an inch Before water is flowing over it, then your cutting it close

 

[pascal32]

What size waves are creating?

 

[Randrew215]

It's 3/4" either way. I'm not specifically looking to make large waves, but I'll be running two MP40s (which I haven't run together on my current setup) and I don't know how wavy they get at the surface. I'm sure it depends on what mode I run them in though.

An additional question:
I haven't set the baffles in my sump yet. The sequence of the sump is drain pipes chamber, protein skimmer chamber, return pump (mag 12) chamber. My skimmer purportedly runs best at a depth of 6.5" and I don't have a huge amount of room to elevate the skimmer due to space constraints and because having a low sump volume gives me peace of mind that it won't overflow in the case of the return pump being turned off. I noticed yesterday that the return pump creates a whirlpool and sucking noise at a depth of 6.5 inches that I don't want to have to listen to all the time. Is there a way to prevent this at that depth or am I resigned to raising the overall water level in the sump?

 

[saltyscotsman]

had the same problem with my pump had to raise water level

 

[Gary Majchrzak]

here we go again

here we go again

*disclaimer*
I have no idea what kind of animals you want to keep in that aquarium
or even if it's YOUR aquarium

but I'd suggest to ANYBODY that wants to create waves in their reef aquarium to strongly reconsider what they're trying to accomplish.

Seek to create a gyre- NOT WAVES.

Acheiving a gyre will create it's own "waves" ...and they'll be the right type.

Hey Andy- get the build thread up!

 

[Randrew215]

Okay- I appreciate the advice and have been making progress!
With regards to my first question above the wave height, I don't think it will be an issue as I'm *not* trying to make waves. I understand the gyre concept and need to think if I can implement that. I drilled my return through the tank back in two separate bulkheads with one in the middle and one on the right hand side (if you're facing the tank). I'll think on this today to see if I can achieve circular flow without having an excess of pvc in the display.
My second question actually solved itself when I realized that I have much more overhead room to remove my skimmer cup than I had originally thought (like 10 extra inches), which means I can indeed raise the sump level and silence the return pump.
I appreciate all the input!! I do apologize for all of the questions without pics. I'll do my best to put up the build thread tonight.
-Andy

 

[iamwrasseman]

i totally agree with gary as i have a 210 with two mp-40s , running on a short cycle master /slave and if i get the pumps within 6" of the water surface then there geta a large top surface wave the closer i get the pumps to the surface . if i submerse the pumps bu 10" or more then i get hardly and surface wave action but i get a great internal water "pulse" that gives my corals a great back and forth swaying motion and its not anywhere as harsh or quick on the corals which works great IMO .

 

[Randrew215]

Thank you, but I'm happy to report that the current system works. It is very easy and inexpensive to fashion an overflow box from glass and silicone.

I realize I still haven't posted a build thread. Official move is Sunday and I'm swing shifting this week, I'm just looking for a couple of hours of free time that haven't come yet to show my progress to URS.

 

[pascal32]

I know BRS just started offering internal overflow boxes.
http://www.bulkreefsupply.com/store/catalogsearch/result/?q=overflow+box

Might be worth checking out.

On quick glance it looks like these boxes are made to be siliconed in. Wouldn't be suprised if these are much louder than the glass holes boxes.