Airstone in Skimmer?

[arrowheadpuffer]

Just wondering, but why not place a airstone in a skimmer to increase the bubble amount? Wouldn't it help to add more air > more bubbles > more skimming?

[cloak]

Check the mods on the Seaclone.

[kyrin01]

Anything above 13% air volume inside the skimmer body will cause the skimmer to run to "lean" to produce any skimmate. Most good skimmer companies account for this in their design.

[JDMhoes]

dont go for the air stone skimmers. they dont work as good. what size is yoru tank?

[cloak]

Don't ever forget that you can run a great tank without one. My Seaclone is jamming right now. "It's a good thing."

;)

[richardhmc]

airstone don't create as much fine quality bubbles as other methods of skimming in protein skimmers imo.

[cloak]

airstone don't create as much fine quality bubbles as other methods of skimming in protein skimmers imo.

Define fine quality bubbles. Venturi? Baffles baffle me...

[Frick-n-Frags]

I still have 2 old Sanders HOB skimmers that used limewood airstones.

limewood evidently was the best solution to gettng super-fine bubbles vs those pressed mineral ones. limewood also does disgusting things after being soaked in the tank for x months.

so, basically, the airstone is going full circle back to the earliest skimmers.

[David Jr.]

Don't airstones clog too?

[der_wille_zur_macht]

so, basically, the airstone is going full circle back to the earliest skimmers.

As with nearly everything else in this hobby. I think you could relate the frequency of certain fads to the average length of time the average tank runs for. :D My earliest skimmers were all airstone-driven countercurrent skimmers. Back then, it was all about dwell time. Now, most "high end" needlewheel skimmers (except the recirculating ones) feature very short dwells.

The right limewood airstones can produce bubbles finer than just about any other method, and it's a perfectly fine way of powering a skimmer. They do clog over time, but you can clean them. Most people would keep several extras, so you could swap the stones in the skimmer out with clean ones, then soak/clean the dirty ones and repeat the cycle.

In the end, it doesn't really matter *how* you are producing bubbles, as long as you're getting certain parameters correct:

1) Dwell time - the amount of time water spends in the skimmer body, in contact with bubbles, before it's expelled back in to the tank. Longer is better - depending on how polarized a given protein is, it'll basically take a certain amount of time to "attach" to a bubble. One school of thought promotes long dwell, since it means you'll be able to remove a higher percentage of proteins. Other schools of thought basically operate on the principle that it doesn't matter, since those "difficult" proteins will just break down into something else that's easier to remove.
2) Volume of air in the skimmer vs. volume of water - up to a point, more air is always better. The vast majority of skimmer designs don't really maximize this variable, because the "best" design for other criteria won't allow for a saturated mix. Instead, most skimmers are limited by:
3) Air volume vs. neck size. If you've got a small neck, you'll never be able to saturate the water in the skimmer with bubbles. As you add water to the skimmer body faster, it just flows back in to the tank faster. As you add air faster, the "foam velocity" up the neck increases (the air you're adding has to go somewhere to get out - it travels up the neck with the foam and escapes through the vent holes or out the lid in the collection cup.) Once you reach a certain air velocity in the neck, the foam will just collapse.
4) Bubble size - Smaller bubbles means more surface area for a given air/water mix; so smaller is pretty much always better.

Of course, there are competing views on which of the above parameters are most important, and/or what the ideal way to approach them is. Unfortunately, there has been VERY little objective research on proper skimmer design, so we're more or less at the mercy of the market or our own DIY experiments. And, again, unfortunately, since most hobbyists only have firsthand experience with a small number of skimmers (and maybe not even in equal conditions) it's hard to even give subjective advice. Hence with anything in the hobby, do your research, and try to verify claims from multiple sources instead of just following the current fad.

[KafudaFish]

airstone don't create as much fine quality bubbles as other methods of skimming in protein skimmers imo.

I have read from many reefers that have been doing this for years that limewood air stones produce the finest bubbles around. It is bubble production that declines over time.
I run a wooden air stone every now and then off a tetra lift pump and the bubbles are just as fine as the bubbles being produced by my tunze skimmer pump.
I wonder if like so many other aspects of the hobby, the skimmer companies realized that profits were not that high off of small chunks of porous wood vs. a new pump?

[cloak]

Don't airstones clog too?

These small wood airstones I'm using in my Seaclone usually last about a month before production goes down and they need replacing. I think there only like $4.99 for two of them so it's not that bad.