Surface skimming question

[bmk]

Hi
My tanks has been up and running for 13 weeks now and is looking good, I am going to get a CUC when I return from holiday in a couple of weeks. The question is the surface always seems to have 'a film of scum', I have the Eheim spray bar breaking the surface on the left of the tank and a MJ900 pointing up at the right hand side but still the 'scum'. I have just looked at a Aquamedic skim box 'http://www.aqua-medic.de/seawater/en/13/skim%20box/' and wondered if any one has ever used one to good effect or what do you guys use.

Thanks

Barry

[der_wille_zur_macht]

Something like that will work. I see you have a skimmer on the tank - is it hang-on? If so, you might investigate options from the manufacturer. Many companies that make hang-on skimmers have add-on surface skimmer boxes.

Alternately, you could build your own. It would just have to be a little acrylic box or other container, with a lip a few mm below the water surface - big enough to contain the skimmer's intake pipe or pump, and with provision to clamp it to the tank's wall or said intake plumbing.

I'm emphasizing the skimmer here since that's where you want the dirty surface water to end up!

[bmk]

Thanks for that. my skimmer is a HOB, should I just cut the intake pipe so that it is just under the surface, at the moment it is about 6" under water.

Barry

[XSiVE]

Do you have the option to run a small sump? Even something like a 5 gallon bucket?

If you couldn't position a surface-skimming box/overflow around the Protein skimmer's intake, you could always get a HOB overflow box to dump down into a sump and then a small powerhead to push the water back up and out near the protein skimmer's inlet.

[XSiVE]

Originally posted by bmk
Thanks for that. my skimmer is a HOB, should I just cut the intake pipe so that it is just under the surface, at the moment it is about 6" under water.

Barry

I wouldn't do that.. I think what DWZM is talking about is actually building a box around the skimmer's inlet and letting the water cascade over the edge of the box.. Just build it so it goes low enough to contain the whole skimmer inlet, no need to cut it.

[besl]

That skim box from aqua medic looks like a great device - unfortuantely my web search is only showing places in Eurpope that sells them - anyone know a US retailer for these?

[XSiVE]

Here's a quick sketch of what you could build to go around your skimmer's inlet pipe.. the light green indicates approximate water level inside the box as well as water level near the top to cause it to overflow into the box and then get sucked up by the skimmer.. this will pull all of that nasty surface film off for you.

[der_wille_zur_macht]

Nice drawing. Did you use google sketchup? I'm just breaking in to that myself.

And yes, that is pretty much what I had in mind. you DON'T want to just cut the intake pipe, otherwise it'll suck air. The intake pipe needs to be well submerged. The trick is to put a box or container around it. This container's lip being just below the water surface will mean that the only water in it has been skimmed off the surface. Hence, the skimmer intake will be sucking in surface skimmed water.

Basically, what you want to do is imitate the "in tank" half of a hang-on overflow, but with the skimmer sucking the water out of it instead of a siphon pipe leading to the outer box of a typical hang-on overflow.

If you look closely at the device originally linked to, you can see that it's basically doing the same thing I have described, but with an additional inlet down inside the tank. There are a few similar devices available here in the states - Drs Foster and Smith sell one meant for use on a canister filter, except it's cylindrical instead of square.

[XSiVE]

Yep, that was done in Sketchup. I decided to download and learn it yesterday since I had heard it was pretty easy.

Drawing this stuff up in 3D makes explaining things SOOOO much easier(for me anyway, im a visual learner), whether it be helping someone else, or asking for help and trying to express what you're thinking

[der_wille_zur_macht]

Have you found any good libraries of plumbing parts or other objects relevant to reef keeping?

(don't mean to get the thread off topic here, just taking an opportunity!)

[XSiVE]

Nah I have not gotten that in-depth yet.. Im more learning the basic shapes, tools, and how to make them work together to create something worth looking at...

It's a lot easier than it seems. I worked for an hour playing with circles and lines to create a cylinder like seen in that drawing above when I realized it was a 2-step process

Maybe some of the guys in the DIY forum will know where to find aquarium/plumbing related libraries.

OK BACK ON TRACK NOW
surface skimming is important

[lesages]

I've got a Aqua Medic Skimbox that I bought for the same reason. It worked pretty well but was a bit too bulky for my tastes so now I have a surface skimmer for my Fluval which is a bit more aesthetically pleasing.

[jhentr]

If you want a cheap DIY project, you can rig something up for free until you do decide to get yourself a skimmer box, etc. Below is a description of my DIY surface skimmer for my HOB Skimmer. It's a lot of trial and error, but by the 4th one, I think I've perfected it.

1. Get a plastic water bottle (16 to 20 OZ). You can be creative and get the Desani water bottle, which is a light blue, etc.
2. Invert the bottle and cut off the bottom (1/2" to 1" from the bottom). You'll have to play with this depending on how low your HOB filter intake goes.
3. Cut in 'intake' grooves to your "new bottom" of the water bottle. i.e. I used my index finger for spacing on where the grooves will be cut. Depending on your inhabitants, you can vary the groove sizes. Mines was 1/4" each since I don't have snails. Just hermits and big fishes.
4. Slip the bottle over the intake and one or two of the grooves from the bottle should catch onto the bottom edge of the HOB filter. The filter's suction should then hold the bottle in place. I have my HOB skimmer intake pushed up to my right rear corner. The pressure of the skimmer intake and bottle up against the glass also keeps it in place.

Tips.
1. If the filter is sucking in more water than it can pull in, you will need to cut little grooves into the middle or bottom of the bottle to increase water intake. Or cut more or bigger intake grooves at the top to drawn in more water.
2. You can pierce little holes on the side of the bottles and use suction cups to hold it to the glass too.

Keep in mind, it'll probably take you a 4th or 5th bottle to design one that's 'perfect' for your setup, the 1st bottle will just be for you to see what needs to be redone/fix. The easiest thing is that the bottles are usually free (from the recycle bin) and abundant.

I got my idea from the link below.
http://www.reefs.org/library/diy/diy2.html

HTH.

[bmk]

Many thanks for your input on this guys.

Barry