• How to Clean your Skimmer, with style!

    Over time, protein skimmers often need to be restored to their original state, which means they need a deep cleaning. If the sump contains a lighted refugium, coralline algae may have grown within the skimmer's reaction chamber. The pump(s) will also require full dis-assembly to clean out slime or calcification on the impeller's magnet section. With a thorough cleaning, the skimmer should return to peak performance pulling out the maximum amount of skimmate daily. By doing this periodic maintenance, hobbyists can quickly discern if parts are in need of replacement or repair, hopefully prior to sudden failure.

    When it comes to my skimmer, its large size requires that I have an equally sized vessel to hold it for a serious soaking. I prefer to set it up outside and let it run in an acid bath for an hour or two. If you are uncomfortable with using muriatic acid (HCL), plain white vinegar works as well, but you'll have to let it run for multiple hours or even overnight. My supermarket carries white vinegar by the gallon jug on the aisle where salad dressings are sold, and muriatic acid is sold in the pool section. Home Depot sells two 1-gallon jugs in a box in the outside Garden Department, and of course it is available at any local pool supply store.

    I've been using a Euro-reef CS 12-2 since 2005, and with its two Eheim pumps, the vat needs to be about 20" x 18" and that isn't an easy size to find. Even a common 33g trashcan doesn't have a wide enough diameter to accommodate the entire unit, so I decided it was simpler to just build the perfect Skimmer Soaker(TM) out of acrylic, of course.



    The project is 22" x 22" x 8", using 3/8" material for the walls and 1/4" for the base, holding roughly 15-gallons to the top edge. A sheet of 3/4" foam was placed beneath it to protect it from damage on the concrete. For the heck of it, I ran a bevel router bit around the top edge just to give it a little attitude, and a melevsreef sticker for style.

    The skimmer fit perfectly with a little room to spare, and I filled it up with tap water from the hose. I ran the power cords from the pumps to a 6-way outlet strip elevated on a plant stand, which eliminates the risk of electrocution if water were to trickle that direction.



    Once the skimmer soaker was filled with water, I turned on the Eheim pumps. After the skimmer filled up significantly, I slowly poured in half a gallon of muriatic acid into the skimmer body. The gate valve was adjusted to increase the water & acid solution to the neck of the skimmer and it was left to run like this for about an hour.

    Note: Whenever using acid and water, you ALWAYS add the acid to the water; not the water to the acid. This prevents being burned by the HCL! When done with the cleaning project, have a safe place to pour out the acidic water because it will leave burn marks wherever it made contact. If your patio area is your only work area, be sure to hose it down constantly to dilute the acid and avoid etching the concrete white.



    With my little acrylic container, it was obvious to me that once the pumps were turned off, it would overflow. That didn't matter this time of year when my lawn is still in winter-mode. It returns in the spring, green and beautiful.

    After about an hour, I wanted to wipe off the coralline algae inside the body of the skimmer, but didn't want to burn my skin from the acid. So I created a scrubbing tool with a 2-foot piece of PVC, a few rubber bands and an old t-shirt. With my makeshift mop in hand, I lowered the water level in the skimmer and ran the balled up t-shirt inside the walls of the skimmer body until most of the algae was off.



    Raising the water level higher, I made the skimmer overflow the body for another hour to get the outside prepped for cleaning. It also poured over the external plumbing section to remove the salt encrustation. In this next picture, you can see the t-shirt mop in the back left corner of the acrylic tank.



    Once it looked as clean as could be seen with the polluted acid water flowing through it, I removed both pumps and submerged them in a bucket of tap water, and let them run for another 20 minutes while I removed the acrylic section and cleaned it thoroughly with rinse water.



    Not bad for a five year old skimmer! The pumps were ready for careful dis-assembly, and were wiped down externally and cleaned with pipe brushes and a tooth brush to remove all the built-up slime within. The impellers were meticulously detailed to make sure there was no damage or worn areas. One nylon washer was replaced because the center hole was no longer perfectly round and I felt it might affect pump operation.



    The coverplate has a venturi nipple that needs to be obstruction-free, including calcification or rock-hard salt accumulation. Using a fine pipe cleaner, the hole is scrubbed clean from both ends to maintain the most air flow through it. The tubing is also rinsed well to make sure it is salt free.





    Once everything looks good, it is reassembled.



    Then I did the same with pump #2...



    With everything clean and ready, it was reinstalled in my sump. Doesn't it look like it is full of milk? That's a good sign.





    Operating as it should, bubbles quickly began to form in the neck - larger at first but it settled down within a couple of hours.





    If your skimmer is smaller, this task is far easier to accomplish. It is important to keep the skimmer operating at peak efficiency if you want it to maximize skimmate output. I continue to recommend that hobbyists clean out the collection cup daily and clean the neck at the same time. Removing that waste regularly has two benefits: #1) the smell is far less intense because it hasn't sat rotting away for days on end, and #2) if the skimmer does overflow for some reason, only the past day's worth of skimmate is dumped back into the system. This can easily be skimmed back out without harm to livestock once the skimmer is reset to normal operation.

    So what to do with my Skimmer Soaker(TM) project? I could save it for the next quarterly cleaning. It could be used at a future frag swap to show off corals for trade/sale. It even could be used as an Infinity tank like the ones made by Zero-Edge Aquariums... For now, it's clean and put aside until I decide.
    Comments 15 Comments
    1. Tumbleweed's Avatar
      Tumbleweed -
      Very nice Marc. Do you know yet if it is skimming better after the cleaning?
    1. melev's Avatar
      melev -
      It overflowed nicely this morning. lol Definitely back to working better.
    1. Trido's Avatar
      Trido -
      Why do you always insist on reminding me to do the things I would rather ignore?
    1. melev's Avatar
      melev -
      Why do you resist?
    1. duster's Avatar
      duster -
      Looks brand new. Does it have any effect on the surface tension?
    1. melev's Avatar
      melev -
      No, because it was rinsed well. It settled in within an hour or two.
    1. coigula's Avatar
      coigula -
      I have CS8 with Sedra 5000. I clean with vinegar. I'm concerned HCl is too strong but only have sponges growing so not much need for pool acid. I notice it tunes within 1/4 turn from wet to dry skimmate then once a month it over flows so I clean it 2X a week to be safe. I got a bigger sump pump instead of bigger skimmer. I still like this design though. not much to go wrong. I also suck salt water through silicone tube once in awhile to take out salt creep. Sponges that I grow need a soft cleaning pad after vinegar still.
    1. TomNeely's Avatar
      TomNeely -
      ...Now I have to clean my skimmer...


      Thanks for the write-up and pictures!
    1. melev's Avatar
      melev -
      coigula - Vinegar is fine. The HCL works quickly, and thus I can get the task done instead of having to wait a long time. In all the years of using acid to clean equipment, I've never had anything damaged or fail after the fact. Matter of fact, I usually end up tossing out equipment that is simply too old to be reliable, not because it has failed. Decluttering, so to speak. If you are staying on top of the cleaning, there is no need for stronger methods obviously. And the key is that I don't leave it in solution for longer periods of time. What's the reason for the bigger sump pump versus a larger skimmer?

      TomNeely - You're welcome.
    1. Alaska_Phil's Avatar
      Alaska_Phil -
      Thanks for the reminder Marc, I think my backpack skimmer will fit nicely in a 5 gal bucket of vinegar this weekend. The office will smell nice come monday morning though.
    1. robicts's Avatar
      robicts -
      How often do you clean your protien skimmer?
    1. melev's Avatar
      melev -
      Probably every six months. When I can't stand it anymore.
    1. Alaska_Phil's Avatar
      Alaska_Phil -
      Cleaned mine with the acid a couple weeks ago. First time in 3 years. Needless to say it's running like new again. The acid does in minutes what takes hours with vinegar. I'll post before and after pics as soon as I figure out how to get them off the camera (forgot to insert the SD card. )
    1. TBDuval's Avatar
      TBDuval -
      How much acid to water do you add? I know pool acid can be quite strong.
    1. melev's Avatar
      melev -
      I used half a gallon to about 12 gallons of water.