CL Microbubbles

[oharaell]

So I decided to bite the bullet and buy an Oceans Motion, and wanted to plumb it in a CL. I already had a spare Mag 9.5 that I wanted to use.

I've got an AGA RR with a corner overflow. Instead of going over the top for the intake, I decided to use my second hole in my overflow. I used 1.25" PVC about 6" high, goes down into my sump and is directly connected to the pump (figured I'd submerse the pump since I didn't have heat issues, and Mag's are notorious for cracking and sucking in air).

Well... here's the problem now... I've got about 1700 GPH running over the overflow and bubbles are making it down to the CL intake!

Ideas, anyone? I'm thinking about just filling the overflow about half way with LR rubble... but before I did that I figured I'd check and see if anyone had experianced anything similiar.

Thanks everyone!

[oharaell]

Guess I shoulda clarified...

1.25" PVC with a whole mess of holes drilled in it, capped.

[eznet2u]

Do you have a Durso in the overflow?

[oharaell]

Yep...
A durso on one bulkhead. CL intake on the other.

[Pbrown3701]

I would remove the pump intake from the overflow and just do it up and over the back.

You're just running a bunch of water over your overflow that you don't need to. This is:

A. causing more noise
B. reducing the efficiency of your surface skimming
C. Obviously - causing a problem with micro-bubbles

[oharaell]

a) yep
b) Ok... rookie question...
reducing suface skimming efficiency? Can you elaborate a little?
c) yep

[mikej83]

<a href=showthread.php?s=&postid=9805227#post9805227 target=_blank>Originally posted</a> by oharaell
a) yep
b) Ok... rookie question...
reducing suface skimming efficiency? Can you elaborate a little?
c) yep

Proteins, oils, things like that, are found in greater concentrations on the water's surface. You are increasing the volume of water that is coming over your overflow by feeding your closed loop out of the overflow, rather than directly from the tank. The consequence of an increased flow is that you are diluting the bad stuff on top before it gets to your skimmer, ergo your skimmer is processing more water to pull out the same amount of waste.

At least, that's what I think Pbrown means, this is only my second post so take it with a grain of salt :)

Regarding the micro-bubbles, you might have a look at Mything the Point (http://www.reefkeeping.com/issues/2004-01/eb/index.php) , it may be relevant to your situation.

HTH


-Mike

[oharaell]

Yeah, I understand the surface skimming, I just didn't get the reducing efficiency part. If anything, I thought that it would actually be more efficient.

I think I understand now though.... It's "reducing it's efficiency", Since I'm still getting the same results, just sending more water over the overflow?

If that's the case, I'm not really all that concerned. The noise isn't bad enough to be an issue for me, and plumbing over the top is doable, I'd just like to avoid it if I can.

Has anyone used LR in thier overflow? Anything I should be concerned about?

[Pbrown3701]

Sorry for my hiatus :)

Yeah, when you send more water over the overflow, you're making a thicker layer of water go over the weir. This means you are taking more than just the top slice where all of the goodies...er....baddies are.

Then, on top of that, half of the water going over the overflow is being sucked in by your CL pump and dispersed back into the tank. This means your filter and skimmer are seeing much more diluted water.

[oharaell]

ARRGH! You're killing me!!!!

I was just about to go ahead and add LR to my overflow, since the noise (it is a little louder) doesn't really bother me, and it sounded like it really wasn't effecting my skimmers performance.

But, I think what your saying is that it is indeed effecting the performance.... It makes perfect sense now...


I REALLY don't wanna replumb it! :(

[Pbrown3701]

my bad :)

My CL intake simply goes up and over the back of the tank (PVC). I use a "T" and a 90° (exactly like a Durso stand pipe) and this "U" hooks over the tanks and has a strainer on the end. Then on the cap of the "durso" rather than having a vent hole (which would suck in water) I just have a cap. IN order to prime the system, i just open the cap and pour in tank water until its full. Then put the cap on and start the system. as long as the cap is tight, you don't get any air inside after the first minute or so.

[oharaell]

Yeah, I actually tried the one melev has on his site for my squid and got really bad bubbles there too... But... i think there were a few reasons for that.
1) same reason I'm getting 'em now!! DUHHHHHHHHH
2) Mag's are notorious for doing just that when they're used externally... Fixed that this time by actually putting it under water in my sump.

My real problem now is that things are REALLY cramped under the stand (got 6 pipes down there now with my OM and T for 'fuge and skimmer), so going out the back is gunna be really tight.

I'm thinking I just change the CL intake that's there to a riser and go over the top of the wier....

On a lighter note... my acro's are going NUTS (in a good way)...