My Air Troubles

[Tommy Gunnz]

Hey all,

I know that I have been asking a lot of questions about my sump, skimmer, and pumps lately but I have been not been getting many answers at all. I just took this short video of my tank in hopes that maybe someone can help me if they see what is happening:

http/s96.photobucket.com/albums/l162/tom...Mysumpissue.flv

In this video, the first 15 to 18 seconds show the tank without the skimmer running at all. You can see the overflow return pipe coming up from my sump, through the bottom of the tank, and back into the main tank. You may notice alot of bubbles stuck to the overflow chamber and the back glass. This is because when I turn the skimmer on, in the second half of the video, it creates so many bubbles in the sump that they are returned through the overflow return plumbing and into the tank. The problem gains momentum over time and eventually the tank is full of tiny bubbles, resulting in what looks like a 'sand storm' throughout all the tank's water. The second half of the video shows that bubles entering the tank and you will notice that the water flow coming out of the plumbing very clearly.

The water level in the sump is well over the top of the return pump by at least two or three inches. This means that the pump cannot possibly be getting air from the surface to make these bubbles. To further that idea, the bubbles only occur when the skimmer is on.

I have cleaned out the skimmers inner workings as well as its intake pump but while the water inside the body definately looks 'milky' like it should, the water just below the containment cup is very still and not bubbly at all. Do I have a bad skimmer or is there something I am missing here? I cannot stand the looks of the tank with all the bubbles in the water and eventually, it gets hard to see anything in the tank at all. This usually takes about 6 to 8 hours to get this severe and fixes itself pretty quickly once the sump is off. I am lost here and need some help quickly since I am not sure how long my water quality will remain as good as it has been without the skimmer's help.

 

[PaulasPets]

What kind of skimmer do you have? It sounds like you are just pumping too much air into the skimmer, try turning down your airpump a bit. Also, what does your sump look like? If you have a sheet of glass or plastic sepperating the part where the skimmer is located and the part with the return pump, with only a little gap at the bottom, this will trap the bubbles on the skimmer side so they won't get to the pump.

Paula

 

[Tommy Gunnz]

I am using a "Coralife Super Skimmer" which I have seen millions of times in magazines and at LFS around here. The skimmer is in a sump that is exactly as you explain, with a sheet of acrylic seperating the main chamber (with the skimmer in it) from the chamber that the return pump is located. There is a small gap in the bottom to allow the water to get from one chamber to another. Also, there is a sponge, about 2 inches wide, by 3 or 4 inches 'deep' that the water must pass through to get to the return pump.

I took out the skimmer and cleaned it up the best I could. To be really honest, it wasn't that dirty at all, especially in the intake pump. Instead of putting the skimmer right inside the sump, I have it hanging off the front of it right now and the air bubbles are not a problem at all right now. It seems like when I put the skimmer in the sump, the hose that the water exits from is all bubbly and frothy. The air intake is set at its lowest setting right now, and I am getting good 'bubbling' inside the body of the skimmer.

This is boggling my mind because it shouldnt matter where the skimmer is placed that makes the difference, is it? Like I said, I have had this up and running with the skimmer in the sump for over a month and a half with no problems short of the occasional burst of bubbles going into my tank. Usually this is my signal that the sump water is getting low if I have neglected to check it for a couple of days. With the skimmer on the side of my sump though, I can clearly see it through the stand's glass door which is more 'tinted' than it is black to match. I cannot put it on the back side of the sump because of the plumbing.

Thanks for your help so far!

 

[SkiFletch]

Lets see if I can write this in a way that makes sense

A coralife skimmer utilizes a needlewheel pump to do its thing. Basically, air enters the pump through the airline tubing, is chopped up by the very small impeller blades into very fine bubbles and is then pumped into the body of the skimmer through that strange cone-shaped injection cup that resides 3-4 inches from the bottom of the reaction chamber. If any foam pads are utilized, they should be utilized on the skimmer output side, not the pump input. If its placed on the pump input you drastically change the pressure characteristics of the pump and may cause excess bubble formation.

The operation of the pump is governed by how much water sits above it. If the wrong height of water sits above your pump, then you can either have too many or too few bubbles. Something tells me that when you put the skimmer hanging on the edge of the sump, the height is where the skimmer is designed for, and when you put it in-sump, you probably have too much water above the pump.

Good news is that the skimmers also come with ways to tweak them to avoid having too many bubbles. When tweaking skimmers, I usually like to follow a step by step procedure.

-First, place them where they are going to run. (in-sump for you)
-Turn on the pump with airline hose connected and inject as much air as possible into the reaction chamber before the pump starts growling in protest. If too much air is injected, the pump will make a rumbling or rattling sound as the impeller basically freely spins in air. This point is difficult to reach with most thin airline tubing, but if you do reach it, close the tube off a bit to reduce the amount of air entering the pump.
-Once maximum air is entered into the skimmer, you must adjust the red-handled valve on the outlet of the skimmer which controls the height of water in the main chamber. You want the water to go up to the reducing neck of the collection cup. Probably halfway up.
-If at this point, air is still leaving the skimmer through the output try reducing the amount of air entering the skimmer to prevent it from getting into the outlet hose. If you have to reduce the amount of air to none, its safe to say that there is something blocking your output hose. Propping the skimmer up a few inches in the water may correct this, or it may not.

Does that make sense? Hope so, its hard to explain without showing. Just a couple notes, I couldnt see the skimmer in your video, the lighting was too low . Also, fine bubbles are not an immediate danger to fish, but a large danger to soft-bodied invertebrates and corals. Snails, sea slugs, nudibranchs, sea hares, and corals are in bigtime danger with microbubbles in the water as they can cause embolisms on said organisms. Scaled fish are OK with bubbles short term, but should be avoided longterm.