Modifing the Coralife Super Skimmer CSS

October 8, 2009 - 21 minutes read

Saltwater Skimmer – Coralife Super Skimmer

I have created this page to make it easier for people to find fixes and mods for their Coralife Super Skimmers. I went thru all of the Reef Central post, and took out sections that I thought were useful. I have moved the pictures to be hosted off my server since I cant direct link to RC Gallery pics.

Here is how I have mine setup for about a week, while I finish my sump.

Skimmate @ 36hrs

Model: Needlewheel-up 65gal w/ pump
Size: Skimmer is 4 1/2″ x 5 1/2″ x 20 3/4″ high.

Model: Needlewheel-up 125gal w/ pump
Size: Skimmer is 5″ x 7 1/4″ x 24 1/2″ high.

Model: Needlewheel-up 220gal w/ pump
Size: Skimmer is 6″ x 8″ x 25 1/2″ high.

Model: Venturi-Up to 220 gallons pump not included
Size: Skimmer is 6″ x 8″ x 25 1/2″ high.

User Manual / Installation Guide (8.2MB Acrobat File)

For all you people with extra microbubbles or collection cup overflows, a fellow Canadian reefer emailed Coralife about their problem. Here is their response, which might be helpful. I found that this was my problem when I setup my 220.

Thank you, for your most recent purchase of our Coralife Super Skimmer. We are sorry to hear about your experience with our product. It does sound like the skimmer is not set up properly though. The way you wrote your email I understand that you are probably having water come out the air vent on top of the output tubing. If this is the case it sounds as if the bubble trap is not set up properly. You will want to make sure that the top of the bubble trap is at the same level as your water line of the aquarium or 1/16″ above. Make sure your black sponge is on top and the white sponge is on the bottom. Then make sure the end of your outlet tubing is no more than 1/2″ to 1″ in the black sponge (you may have to cut the tubing). What was happening is the skimmer had back pressure on the outlet hose. Since protein skimmers are not pressurized system the only way for water to get out is through the collection cup. That is probably why you where having problems. The other item we include with the model 65 Super Skimmer is a flow control valve. If the outlet is set up properly and you are still having problems attach the flow valve to the outlet of the water pump and valve it back a little. Is your output tubing under water? If so that could be some of the problem. The only way for water to go into the collection cup is because the output has back pressure on it and its not able to get rid of the water going in the unit. The only other problem I can think of is if you do not have the tubing going out and down right away this will also cause back pressure. The output tubing can not run horizontally. Otherwise if none of this is the problem then you can either return it to the company you bought it from or return it to us for a replacement.

Yes cut the tube and place the pump as near to the surface as possible. Everything deeper than 2 inch is too deep. I bet that the water level in you tank is very high?? Only about 1-2 inch below where the skimmer is mounted. Keep in mind that the minimum water level inside the skimmer is at least at same hight as in your tank no matter how open the valve is. If your skimmer is still overflowing when you set up the pump, try to reduce the pump by placing a small pvc fitting inside the tube of the pump. I guess that you have a RIO 1500 or so running on that skimmer?? This pump is too strong when you have very high water level in your tank even if you open the valve completely it is not enough to drain the skimmer.

Ive done away with the flex tube on mine and added a gate valve and bigger vent on the output this seemed to help greatly skims more consistent!

here is a mod I did to the vent to help it get more air works great!!! way better than the plastic hose with a pinhole in the top of it

In a venturi the air is sucked in after the pump(via a venturi valve), in a needlewheel the air is actually sucked into the pump intake, and the “needles” of the needlewheels impeller chop up the bubbles into much finer bubbles. Finer bubbles= more surface area = more protein can stick to each bubble = more efficient.

Wet or dry skimming is preference I think. Most folks with bare-bottom tanks generally wet skim. The skimmate is lighter in color, not as smelly but you get a lot of it. Dry skimming will produce dark, foul smelling skimmate. But less of it.

Wet skimming is generally considered to be better in that you are taking more out in the long run at a faster rate, however you are also wasting a little more water as the skimmate is not as thick and condensed.

I did cut the flexible output tube a bit so it can fit a little better in the bubble diffuser box. Try not to have that output tube go below the water line. If you do that, it will make the skimmer level pulse or cavitate a bit. I did replace that white filter with some of that blue cut to size filter pad that you can get at Petsmart. The white filter clogs up easily and causes to make the water level in the bubble diffuser to overflow. I also drilled out that little hole on the output tube a little bigger. As of last week, I put some carbon in the diffuser box to see if this was going to be a problem. It has been working great so far. So, the bubble diffuser box is a good place to put carbon in.

I also put airline hose over the nipple- so it got rid of the sound immediately

Several people, including Anthony Calfo, suggest keeping the skimmer pump as close to the surface as possible.

I got my pump about 2 inches below the sump waterline directly under the overflow hose output. This is were I get the darkest, nastiest skim I can get out of the CSS.

I normally leave my foam level about 1 to 1 1/2 above the base of the cup.

Since the skimmer is an up, over and down feed, try to have the pump as high to the sump surface level as you can. I have my pump about 2 inches from the water line.

I have been reading and getting some pms from you CSS users about the splashing noise and microbubbles in the tank. SO, i thought about it and did some minor mods to the CSS. The result did reduce the splashing noise and microbubbles, BUT NOT 100%. Its pretty significant though. Heres what you need.
1″ PVC TEE slip x slip x slip
1″ PVC (about a foot should do it)
1″ PVC slip cap
Mag 2 to 7 pre filter sponge.(or equivalent of it)


If you cut all your PVC straight (or should I say square), you shouldn’t need any glue. I didn’t get any exact measurements since theres different setups among us.


Also what is not pictured is on the PVC slip cap, there is a 1/4 inch hole. You WILL need the cap or it will be really loud.


So not only it reduce SOME noise and bubbles, it also eliminated that big diffuser box that everybody loves. Ive only got this setup for 1 hour so I am not sure how performance will affect it.

one thing i haven’t seen mentioned yet, is details on the pump used on the 125 – the 65 uses a rio 1100, and the 220 uses an unlabeled taiwanese pump, but can anybody confirm anything regarding the 125’s pump?

Only thing I added was airline tubing by the return.

I noticed that the venturi had collected quite a bit of calcium. Cleaned it out and the skimmer started working wonderfully again.

I got a 1 inch CPVC female adapter and put it in place of the flexible hose it goes on tight but it went on mine great then i use 2 one inch 45 to make a 90 turn short pice of pipe one inch coupling the i got a pre-filer sponge and put it on the coupling it worked very well after the skimmer broke in tho i have very little bubbles any whey i also had leaking when i had my water level up into the neck mine was leaking from the collection cup around the grey ring i ran some # 33 acrylic glue around that ring and i have no leaks now. Later i did a gate vale mod on mine made adjusting much easier let me know if are interested in how i did that and i will let you know.

I would move that pump to about 1 inch from the water surface to the intake.

return hose 1/4″ from water.

I also changed out the filter media that come with the diffuser and replace it with a black sponge that is a just little finer (not fine) and it solve the microbubble issue and an airline where the little knob at the return at and it stopped the sucking sound.

ItemFirst, your skimmer really will need some time to break in properly. The manufacturing oils left on the plastic are detrimental to the operation of the skimmer and need to be dissolved before it will start operating properly. Under normal operation this can take 24-48 hours. You can reduce this time by running it through the dishwasher (not the pump!!) to remove the oils.
ItemIf you are running your skimmer in HOT (hang-on-tank) mode, the instructions tell you to submerge the pump 8″ below the waterline. This is far too deep to get proper bubble production. Cut the plastic tubing so that the pump is only 2-3″ below the water’s surface. This will cause more air to be drawn into the venturi and increase bubble production.
ItemThis tip can solve THREE common problems that I have seen with this skimmer: Excessive microbubbles escaping into the tank, water leaking/shooting out of the output tube vent hole, and irritating water level fluctuations resulting in inconsistent skimmate production. Cut the flexible output tube so that it is NOT submerged in the water. The stock tube is too long and it reaches it all the way to the bottom of the diffuser box, causing massive back-pressure and tons of bubbles to flow into the tank. Cut it so the end extends just into the bubble diffuser sponge (which should be slightly above the waterline anyway).
ItemPull the black sponge in the diffuser box so it is about 1/4″ above the edge of the box itself. Along with tip #3, your output tube should extend into the sponge, but not below the water level in the center hole. This will prevent bubbles from flowing over the top of the sponge and into the tank.
ItemGot back-pressure problems or water literally shooting out of the output vent hole? Drill out the hole so that more air can escape from the tube. You can also slice the nub off entirely and drill out the hole that way. Though depending on how much return flow you have, this may cause a bit of splashing/spray from your hole.
ItemBe PATIENT! This is a great skimmer for the cost, but it does require some attention to get it working properly. Make small adjustments to the red knob and wait and see how your adjustments affect skimmate production.

Some more tips that I believe maximize performance for sump use:

ItemHave the skimmer pump as high as you can. About 2 to 3 ” should do it.
ItemSomebody correct me if Im wrong, but try to maximize flow in the main tank. I think increasing flow helps push up all that gunk up into the overflow and sucked up by the skimmer.
ItemHave your skimmer pump as close as you can to the overflow output.
ItemOkay, next tip is not a sump use tip. If used as a HOT, try to maintain the water level in the main tank constant. During the summer days, evaporation rate is gonna be pretty high. An auto top off can cure that. Also having a sump leaves the water level in the main tank constant(just make sure you check the water level in the sump daily)

I had these problems when I added my sump (already had been using CSS Hang On Tank).

Itemthe new water added from the sump increased the total volume of water in the system which in a way simulatea a huge water change. Give it a while to settle down could be 2 weeks.
ItemHave the skimmer pump about 2-3 inches below water. I have mine right next to the overflow intake and it is skimming some really dark nasty stuff.
Itemmake sure the skimmer is level. I had mine unleveled and it leaked at the adjustment knob and didnt skim. I then made sure it was level hanging off the back of the sump. If you have it in sump mabye try to have it hang off the back. it seems to work better that way.

The valve fits between the pump and the clean tubing but is not necessary unless you are getting too much flow from the return. and if u want the return to fit better in the bubble diffuser you can move the part that hooks on to your tank on the main body of the skimmer down a bit so it sits higher on your tank.

If you just installed it, set the foam level really low for a couple of days. It could take up to 48 hours depending how well you rinsed it. Once you see some skimmate, raise the level a bit. Keep doing this daily till you are satisfied with the skimmate it is producing.

Tried the sponge pad (supplied with the skimmer) underneath the diffuser sponge – that resulted in inconsistent bubble level in the riser tube. Tried putting some floss underneath the same sponge – that produced bigger bubbles coming out of the bubble diffuser box and inconsistent bubble level.

This is what eliminated the micro bubbles – I placed the grey sponge vertically in the diffuser box with the return tube resting on top of it (I had to cut some more of it off). Virtually no noise, consistent bubble level in the riser tube and very few micro bubbles (just a few in immediate vicinity of the diffuser box) and some nasty smelling skimmate . BTW, the edge of the diffuser box is about a 1/4″ from the water surface.


Skimmer pumps are better up higher. The protein or scum that a protein skimmer skims is actually lighter than water so it floats to the top. Having the pump 2 to 3 inches below the water line helps suck in that gunk since its higher up. This is especially important on skimmers that are used as a HOT.

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