Mr. Saltwater Tank

Mr. Saltwater Tank TV Friday AM Quick Tip #132: The Surface Scum Removal Service You’ve Already Paid For


Surface scum is unsightly and really ruins the look of your saltwater tank. Have no fear though, there is an easy fix to the surface scum problem that is already in your tank waiting to be used. Hint: It’s NOT your overflow box!

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Comments for this article (33)

  • Richard says:

    I can’t see the video Mark.

  • Hit refresh on your browser Richard. It’s there.

  • Jason says:

    Happy Scum Skimming!! ROTFL!!! 🙂

  • chad says:

    Mark,

    Would it hurt to run say a 20 minute off cycle on my powerheads sometime during the night every night so I won’t ever have to see the scum?

  • chad…that won’t hurt at all. That’s what I do with my power heads.

  • Jason…no one should tolerate scum!

  • Phoenix Bailey says:

    Awesome tip. What if your overflow is under the water surface? And does not skim the surface? Eg herbie overflow?

  • Ryan B. says:

    I like the gentle wave action you have going on. Is that from the Vortechs? Or do you have a wave box or something else?

  • Brent says:

    +1

    I have a Marineland cornerflo tank with the overflow inlet both above and below the water surface….the water tends to go through the underwater inlet first, with the surface one being mildly effective.

    Any suggestions?

  • Kevin says:

    I have a 60 cube with that slim PITA overflow Brent. I have been using blue filter pad to “block off” the lower intake. I just take the overflow cover off, trim a three ply strip of pad to fit into the top behind the cover, and ease the cover back in place. I still get small spots in the corners where my MP 10 and Tunze trap it. I’ll have to give Mark’s tip a try tonight after work!

  • Matt says:

    Very nice idea I hadn’t considered… Useful for spring cleaning days when stuff gets stirred up or our engineers decide to move house again! I’ll give it a go… 🙂

  • George Drapaniotis says:

    Hey Mark! Great tip but I have a question.. How do you remove the surface scum when I only have a HOB filter and protein skimmer on my 75g reef aquarium? Any help would be appreciate! Keep up the good work!

  • Brent & Kevin…you guys seriously don’t get much flow over the top of the overflow b/c most of it comes through the center holes? That’s strange. My 90g tank was a marineland tank with the corner overflow and I got SOME flow through the center inlet, but not much.

  • George Drapaniotis…the easiest way to do is to suck it off when you siphon out water for water change. You can hold the tube just below the surface of the water such that it sucks the surface scum off and a little bit of air, but not too much air that it breaks the siphon.

  • Brent says:

    @Mark,

    this is indeed true. The center inlet has a lower “lip”, so water will take that exit first. the “skimmer lip” is about a half inch higher…a few drips will go over, but the bulk is routed to the center. If I remove the overflow “cover”, then it will function as just the surface skimmer (without the teeth) but it obviously looks ugly.

  • Brent…is this a newer design? I got my 90g in ’09 and I don’t remember a lip on the lower inlet, just some slots molded into the plastic

  • Mad Hatter's Reef says:

    Great tip Mark. In the past I’ve had trouble with scum build up on the surface of the water. It would really drive me nuts when I would look up through the aquarium and see the scum floating around.

    Love the blonde naso tang 🙂

  • brent says:

    Don’t the vortecs reset if you power them off? Mine are set to night mode which is when I would like to do it, won’t that cancel my night mode if they get powered off with my rake?

  • Brent says:

    @mark,

    My tank was built in Sept 2011..

    not my pic, but you can see from this what’s happening:
    http://i667.photobucket.com/albums/vv38/SimonSKL/125%20gallon%20build/003-1.jpg

    The portion that has the comb/teeth part is removable…its a piece that goes down the whole front of the unit, and has the teeth for the upper and lower intake…without this piece, the overflow is essentially a big wall in the tank…the water will go over the wall, which is still the same place as with the piece installed…i never get a good burst of water thru the upper teeth…

    I’m at work now, if you would like me to take pics of me setup and email you I can. I’d be glad to get this working, i’ve had to turn down my mp40 so the scum gets sucked out..

    I’m also using a 500gpm return pump in my 65g display (wanted a slow flow for finer skimming)…could this be the problem?

  • Kevin says:

    @Mark. It’s the “Corner-Flow” overflow that has issues. It is positioned at the back pane of the tank and is maybe 24″ high x 12″ wide x 2″ deep. They actually install the bulkheads in the back pane before siliconing in the slim overflow. I would have opted for a non-reef ready model and added a coast to coast myself had I known.

  • Barbara says:

    Does it hurt to angle the power heads up some to break the water tension? I started doing that and have not seen any scum.

  • Dale says:

    I have my return nozzles just below the water surface and that keeps my tank scum free

  • George Drapaniotis says:

    Sounds good much appreciated Mark! 🙂

  • Barbara says:

    I have my return nozzles there also and it pushes most of it to one side but does not get rid of it.

  • Barbara…it certainly won’t hurt and there can still be pockets where the scum can’t get past the turbulent water that the powerheads create.

  • Mark H. says:

    Good tip Mark, all in favor of Mark installing a webcam on his tank and giving us access say, Pleeeeease… 🙂

  • Matt says:

    Ahem — pleeeeease — cough,cough…

  • Robert says:

    Mark
    Summer vacation is upon us. I am going to be gone for a week. I live
    By my self and have no one to tend to my tank. I do have a water make tank take care of evaporation. Not sure how to feed or empty the skimmer.
    Any suggestions how to prepare this week long absence.
    I know you travel a lot, who takes care of your tanks?

  • Ted says:

    Mark
    What are your views on the “Coast to Coast” Beananimal Calflo overflow box which in theory suppose to Super Skim the entire surface of the water.
    Is this a old technology since our Protein skimmers and methods are better now or does it still Hold water?

  • Ted…I’ll use a coast to coast overflow on certain applications where it is needed. Otherwise I stick with the standard overflow box because it works well. I think a lot of people get carried away in making things more complicated than they need to be.

  • Don says:

    OK in my 125 gal I have 2 returns & 2 over flows both side by side in the back corners (its a pre drilled tank) I have no power heads what I did was run the returns over to the sides ran them about 1/2 way down blowing like at a slight angle toward the front of the tank. The over flow pipes are basically skimming the top. But I have a lot of the scum on top still. What to do??

  • Don…since you have no powerheads you’ll need to reposition your return lines so that there are no pockets where the scum gets trapped. Also make sure the water is flowing down through the overflow teeth on your overflow box. If the water inside the overflow box is the same height as the water in the tank, you won’t get any surface skimming action.

  • Jerry says:

    I have at least a pair of pumps, in each tank, that keeps the surface extremely agitated. I’ve yet to have any dead spots but I’ll have to check again, to make sure. I believe that surface agitation is vital to maintain cooling through evaporation and certainly helps with nitrate removal. Not sure of any downsides but would be interested to know if there are

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