Micro-Bubbles

[emthenson]

I have a 93gal open-top cube that has been set up for a little over 3 weeks. I have added 60 lbs of rock and 80 lbs of sand. It is 30x30x24 with a single corner overflow. I had a mag 9.5 in the sump but temps in the afternoon where around 84 so I decided to mount the pump external. Now the temp is perfect but I have microbubbles. I have included a drawing of the plumbing. The return is plumbed with 1" pvc and I have a tee just above the pump that reduces to 3/4" for a quick tubing connect for water changes and such. I do hear some crackling at this tee. Can a tee cause enough tubulance to cause bubbles? I do not remember these bubbles when the pump was internal. What do you think?
<fieldset class="gc-fieldset">
<legend> Attached files </legend>

>

class="gc-images" title="Tank return.jpg[/IMG] style="max-width:300px" /></a> </fieldset>

 

[theplatypus]

The crackling noise is probably the sound of air getting sucked in. You really don't need or want (imo) that much flow through a sump.

 

[steve]

If the pump is pulling water through a crack or something then yes there will be bubbles. But just my two cents: Mag drives can be used external, but in my experience they shouldn't be. I'd feel more comfortable them being used as internal. If you want external, get a real external, such as a GenX or an Iwaki.

 

[dakota9]

I'd look into down sizing the return pump to a mag 5 and run it internally, thats just MO.

 

[emthenson]

I started out with a mag 7 It could not keep up with the overflow. I have the overflow gated down now and the water level is just right with the 9.5. Im new to this so I am up to any sugestions.

 

[weaglereefer]

How is it set up? You should not put anything on the overflow to restrict it. It sounds like you are using a straight siphon from the tank instead of an overflow box. If set up correctly, the water will not flow into the sump any faster than it's pumped out.

 

[wbrown]

no thought about cavitation? have you bled water off the tee? does it make any difference in sound post bleed?

 

[emthenson]

I do have a overflow box. If I donot gate the return down the overflow is very loud and very low. It was this way with both pumps in both configurations. The pump is not gated down. I did bleed the tee down I have even tried attaching a short piece of hose and runing it back into the sump.

 

[weaglereefer]

Well something is not right, you should not need to put any kind of restriction on the overflow line, aside from a Durso, Stockman, or Hofer standpipe inside the overflow box.

I don't understand what you mean by "very low". Is this an internal overflow on a reef ready tank or an external "hang on back" overflow? Do you have any actual pics of the setup?

 

[wbrown]

pics would be an immense help in diagnosing this with you.

 

[zavala83]

Is there baffles in the sump? Do you see them in the sump?

 

[emthenson]

There are no bubbles in the sump.

 

[emthenson]

It is a internal reef ready I will not be home for a few days but will post pics of the overflow soon.

 

[weaglereefer]

Do you have some kind of stand pipe in the overflow box? I don't understand what you mean when you say the overflow is loud and low. If you don't have a stand pipe and the water is dropping 18" to the bulkhead then this would make sense, but with a stand pipe correctly installed there should be no restriction.

 

[emthenson]

If i dont gate it the water in the overflow is about 3" lower than the tank water. the water faling along with a little gurgle from the standpipe is loud. I know the bulkheads are 1" but the standpipe above the bulkhead is bigger. the standpipe has two elbows forming a U turning it down and it has a small hole in the top with a small tube.

 

[weaglereefer]

Then you need to raise the height of the stand pipe a bit. The level in the overflow should only be 1-2" below the display tank's water. I know this isn't really relavent to the question you asked, but it could really help prevent a disaster should something jump into the overflow, go for a ride down the tube and get stuck.

 

[pochaxoo]

That's a durso alright, on some systems you can raise this up or down to get closer to the surface and have less gurgle from the 3 inch drop. If your's is not adjustable think about having a slightly longer stand-pipe.

As far as the bubbles, I would immediately suspect the t and reducer, does any water leak out of the connections. Typically the connections that draw some air will leak water when turned off. Can you tak out the reducer and tell what happens when you just run with no connectors.

The reason that pump isn't blowing the tank away is the reduction you have done to 3/4". size that to 1" and it will really go.

Good luck

 

[pochaxoo]

sorry did not look at the picture all 1" pipe, I would still turn it off and see if there are any leaks.

 

[wbrown]

FWIW: I am running a 9.5 on my 90, and it could use a 12..