Air and skimmers

Jaco Schoeman

Jaco Schoeman

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Hi

Can anyone give me a little technical info regarding air into a skimmer? I see a few skimmers (cheapies) suck air from pump's OUTLET pipe, where as skimmers like the TS series do it from the pump's INTAKE, which I feel is obviously better. Your thoughts?

Secondly, is it better to have the air be sucked by a thicker air pipe, or is the standard air piping best?

I have thought about it and to me it is better to go thicker, as you allow more air to enter, however, would this not lead to larger bubbles out the skimmer head?
 
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Air on the intake is better as the needle/pin wheel will chop the bubbles up. Even if you go for a bigger pipe it will still be limited by the hole diameter on the venturi. If you go for a bigger pipe then you should drill the venturi bigger as well.
 
Thanks Manic

So if the venturi has i.e. a 3mm hole, there is no sense in having a 8mm pipe? Makes sense...

But now if you drill the venturi hole bigger, would that cause bigger bubbles in your reaction chamber - something we obviously do not want?
 
The venturi method is best described as bringing the smallest bubbles into the chamber to get chopped up into smaller bubbles. Like so...

\-----/
-\---/-
--\-/--

But ive seen alot that just go straight into the pump as they are and then get chopped out. Like so...

| |
| |
| |

Interesting to understand the difference between the 2.
 
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Okey thanks, that makes more sense too...

Now onto the next question... Why is it that if I sit in front of my skimmer and stare at it, my wife thinks I am crazy? :lol: No but really, if you look at it, I see the bubbles to boils over the outlet, sometimes flows heavily, and then drops back into the skimmer cup neck. Then there is another big bubble coming out, then a million small bubbles boiling over... Can anyone tell me why this is?

Just to bring you up to date, I built my own skimmer, that seems to be doing a great job, although it has only been running for a day. So I just want to make sure what I need to look out for that is needed for a skimmer to be a good skimmer.
 
lol Jaco, can you build me a skimmer aswell...please...lol... Mine I thinks needs to be upgraded, oh and I also love sitting infront of the sump...lol...
 
Thank you for that Sentari. I have watched the first episode on my 3G, and at 100MB per episode my cap will be reached one time...

Our office ADSL is slower than a 56 K dialup modem I am sure, so I will download the video's slowly but surely...

What I have seen in the first clip though, is the pin wheel impellers... Question: Can one replace any normal pump impeller with the same size pin wheel impeller?
 
Jaco Schoeman said:
Thank you for that Sentari. I have watched the first episode on my 3G, and at 100MB per episode my cap will be reached one time...

Our office ADSL is slower than a 56 K dialup modem I am sure, so I will download the video's slowly but surely...

What I have seen in the first clip though, is the pin wheel impellers... Question: Can one replace any normal pump impeller with the same size pin wheel impeller?
Click to expand...

Most of the OTP pumps have normal impellers that can be replaced with pin wheel or needle wheel impellers.
 
The air pipe that enters, the thickness also depends on the length of the pipe you add to the venturi. I added a 3m 25mm flexible tube to my skimmer intake. And I suck air from outside the area the tank is in. Something to do with sucking back air low in O2, high in CO2 that is above your sump back into the skimmer. Rather get fresh air. And it reduce the sucking sound a lot.

Its ok if the venturi hole is still small. As long as air can more freely down the long piece of pipe without being constricted.

Added bonus. My Ozone unit delivers via another long airline tube, that I inserted all the way down inside the thicker flexible hose. So the O3 should not start to react with the air still coming into the skimmer, but rather with the air and water mixture inside the skimmer.
 
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