Bubbles for bubblers

[oldbubbler]

what do you guys think?

Well me, I don't get how a tube drilled, sliced or whatever would even perform up to a standard $2 stone quality. What I've been getting at is fine, fine and finer bubbles. Big bubbles just blow straight to the surface and apart from bit of surface exchange I don't see how they can help oxygenate water at all. Everything mixes together better the finer you cut it - wouldn't oxygen and water follow the same rule?

The fine bubbles cut down your turbulance too even though your delivering more oxygen. As I wrote earlier I've turned buckets into washing machines with standard stones and I'd imagine bigger holes, bigger bubbles (cut pipes etc) it'd only add to the chundering effect.

With these medium pore stones the roots don't get chundered, they just drift in the breeze and the surface tension is fizzled rather than broiled.

I don't mean to sound dismissive, but I really think anything hand made drilled, sliced etc - unless you're one hell of a tradesman with an artists touch, I just can't see them being even half as effective as even your standard $2 stone.

 

[Haps]

The base truth about DO is that water will only hold so much at a given water temp. If you have that at max, whatever you do should give great results.

 

[turbolaser4528]

Well me, I don't get how a tube drilled, sliced or whatever would even perform up to a standard $2 stone quality. What I've been getting at is fine, fine and finer bubbles. Big bubbles just blow straight to the surface and apart from bit of surface exchange I don't see how they can help oxygenate water at all. Everything mixes together better the finer you cut it - wouldn't oxygen and water follow the same rule?

The fine bubbles cut down your turbulance too even though your delivering more oxygen. As I wrote earlier I've turned buckets into washing machines with standard stones and I'd imagine bigger holes, bigger bubbles (cut pipes etc) it'd only add to the chundering effect.

With these medium pore stones the roots don't get chundered, they just drift in the breeze and the surface tension is fizzled rather than broiled.

I don't mean to sound dismissive, but I really think anything hand made drilled, sliced etc - unless you're one hell of a tradesman with an artists touch, I just can't see them being even half as effective as even your standard $2 stone.

True I see what you are saying, Id rather have a broth of fine bubbles too, makes more sense to me, just have had much trouble with stones clogging and not producing a lot of bubbles. I have a 35 watt eco plus 3 commercial air pump (70 lph air) in a 30 gallon res, what stones should I use?

The base truth about DO is that water will only hold so much at a given water temp. If you have that at max, whatever you do should give great results.

Good point haps, but what is the most efficient and effective oxygenation method? big or small bubbles? For efficiencies sake id say large but as far as effectiveness id have to go with oldbubbler with the smallest bubbles or air as possible. Seems as though the roots will absorb it better, idk maybe im just crazy

 

[Dregs]

Dregs being an aquarium guy, you may know of protein skimmers (if you do marine)?

There's an attachment for pumps driving skimmers called a needle wheel - when used with a venturi the the wheel effectively chops up the bubbles and if you've seen a protein skimmer going you know how frothy and aeratated the water becomes in the chamber (even given that salt water holds oxygen more efficiently than fresh).

Anyway it led to one of my brainstorms for aeration when I thought if I just use a skimmer pump with needle wheel as my pump and I'm pumping rich oxygenated water who'd need an aerator at all.

And it worked, and worked perfectly... in all tests in my bathtub. Unfortunately when transferred to my system, the head height from my reservoir to the feed was just too much for it - you lose heeeeeaps of pumping power with a needle wheel and venturi.

BUT - it's something sfor someone to think about if anyone's got a situation where thay can pump without using much head-height. I could find no solution that would've made mine work without a complete rebuild but the test results (on the flat in a bathtub) made me think hard about it. But then i just went with the fine stones instead.

Oh nice.. that never clicked.. I modded my Pan World pump to a DIY needle wheel for my ASM. I may have to order me another pump. My god the amount of air that could be pumped into DWC or any Hydro reservoir would be amazing. I think I like tinkering more than smoking..

 

[Haps]

I spent a lot of time reading about this before I designed my original hydro dwc tubblers, and I set up different air stone solutions in each tub so I could observe and evaluate effectiveness. But of course, it is not that simple, and it is only one factor of the equation.

Some of my reading, and most of my observed results, indicate that most of the oxy transfer occurs at the surface. In that case any size bubble will do, as long as there is enough. If you think that is wrong, answer this, If tiny tiny bubbles were transfering their oxygen under water, wouldn't most of them dissapear before reaching the surface? Even when I increased water depth from a few inches to two feet, the tiny bubbles still reach the surface.

If you want to see and understand more of this, start doing root autopsies after each crop. But understand, this will give you more questions than answers. Many ways work, it is effectvie implementation that makes the difference, in what I have seen.

H

 

[Elcap]

There's an obvious question here that nobody is asking:

Obviously oxygen to the roots is the imortant factor. But, are those roots receiving that oxygen as the air in bubbles contacts the roots directly, or are they getting the oxygen from the truely dissolved o2? I'd imagine both to some degree, but the answer could play a big part in deciding whether you want simple surface churning, large bubble, small bubbles, etc.

I just run a single dual output $10 cheapy in 6 gal of nutes and with the giant root coverage in a dwc, most of the bubbles are actually surfacing somewhere in the middle of the root mass, you can barely even see them.

 

[Carboy]

i had to go straight to the manufacturer for mine - they're usually used more in the trade for bulk type aerating or live fish stock transport or even (and get this) aerating sewererage sludge reservoirs! YUMMY!

AS I said there's ones with such fine bubbles they're measured in microns and you need a compressor to run them - I've never seen them sold direct to public in any hydro/aquarium shop.

. Standard stones, even those corridium ones, breakdown and crumble to dust with the OXY treatment



The best I've found is called FlexDisc Fine Bubble Diffuser. As OLDBUBBLER said they are used in shit pits. Have to get 'em from industrial supplier.

Produces 1 million bubbles per cubic foot. Didn't count them but i'll take their word for it. Takes minimum 1/2 to max. 3 cuft/min to run. For you metric guys that's at least 15 or so l/min on the low end. Depending on what is driving it, bubbles are 3-5mm in dia. About 12" in diameter and has a 3/4" FPT on the bottom. Actually made to attach to a saddle on a 3"or> pvc pipe. Pain in the ass to figure how to weight/secure it down because the airflow makes it want to float. None of that tiny hose crap either. Get as close as you can w/ pump, as straight as run as possible and as big a diameter hose/pipe that is practical. There is resistance pumping air just like there is resistance pumping water. Communicated w/ a guy whose job is figure how to airate and here's what he said:

It's difficult to predict the performance and longevity in your application as we tested it under much more concentrated conditions such as seen a a typical sewage treatment plant. I would think your koi application should be a less harmful environment for the diffuser media. Instead of the perforated rubber membrane of the units you purchased from us, the ALAB diffuser material is a woven fabric. The best description I have is it looks like your blowing air through pantyhose material that's glued to a mortar board. It does produce some very fine bubbles in clean water, but the technology we market can easily reach DO saturation as well with very little extra airflow. I don't believe it has the longevity of our unit, which is easily 10 years at 24/7/365.​

Application Engineer - Envirex Aeration & RBC Products


I had asked him to compare theirs to this: www.alabdiffusers.com
which cost a hundred fucking dollars for a square foot !!!! not including the oh so generous warranty of 90 days. Hummmm, let me think about that for awhile.......... OK i believe i'll go w/ the 25 buck one that'll last ten yrs.

You hear all sorts of Rules of Thumb: 1watt per gal or 4watt --- 12in of airstone per so many cubic foot etc etc. That's all fine and dandy but can be really misleading. To cut to the chase it comes down to volume of output (pump), how much volume comes thru diffuser, bubble size out of diffuser, water temp. and rez size. One of the most important things that is usually ignored is rez DEPTH. All other factors constant, the taller the column of water the more dissolved oxygen you will have. Also unbelievable the difference of a few degrees H2O temp can make. Same as depth -- everything equal -- colder > DO. If it is REALLY REALLY important to ya, go to www.sperdirect.com and get a DO meter. Be prepared to step up to plate w/ 4 to 800 bucks. For most, not necessary. Running large hydro. my advice is to get it. Otherwise, you are wetting your finger, putting it in the air and trying to tell wind speed.


​

 

[Carboy]

Whoops --- case of head up ass.
Here's the diffuser link

https://usabluebook-onramp.com/docs/images/41.pdf

The one on the lower right of the page. Contact # and all there too.
Change the 41 in address to 40 and you can get more info.

Major bitch to order --- set up acct. company name and on and on and on.
But they did include a half dozen Tootsie Roll Pops w/ the order !!

 

[turbolaser4528]

I spent a lot of time reading about this before I designed my original hydro dwc tubblers, and I set up different air stone solutions in each tub so I could observe and evaluate effectiveness. But of course, it is not that simple, and it is only one factor of the equation.

Some of my reading, and most of my observed results, indicate that most of the oxy transfer occurs at the surface. In that case any size bubble will do, as long as there is enough. If you think that is wrong, answer this, If tiny tiny bubbles were transfering their oxygen under water, wouldn't most of them dissapear before reaching the surface? Even when I increased water depth from a few inches to two feet, the tiny bubbles still reach the surface.

If you want to see and understand more of this, start doing root autopsies after each crop. But understand, this will give you more questions than answers. Many ways work, it is effectvie implementation that makes the difference, in what I have seen.

H

this is a great point, you are correct the bubbles don't dissipate before reaching the surface, I cant believe i never though of that. thanks man, you are a gosh darn genius!!!

There's an obvious question here that nobody is asking:

Obviously oxygen to the roots is the imortant factor. But, are those roots receiving that oxygen as the air in bubbles contacts the roots directly, or are they getting the oxygen from the truely dissolved o2? I'd imagine both to some degree, but the answer could play a big part in deciding whether you want simple surface churning, large bubble, small bubbles, etc.

I thought the same thing, it seems a bit of both perhaps, but if the water is saturated with oxygen then it wouldn't matter if the bubbles hit the roots directly correct? I think we need to figure this out for sure.

Whoops --- case of head up ass.
Here's the diffuser link

https://usabluebook-onramp.com/docs/images/41.pdf

The one on the lower right of the page. Contact # and all there too.
Change the 41 in address to 40 and you can get more info.

Major bitch to order --- set up acct. company name and on and on and on.
But they did include a half dozen Tootsie Roll Pops w/ the order !!

That looks pretty sick my friend, not so cool how you have to sign up and register and all that stuff, but that thing is cheap, well made, and I would love to see it in action. What about clogging with this one? thnx

 

[oldbubbler]

The best I've found is called FlexDisc Fine Bubble Diffuser. As OLDBUBBLER said they are used in shit pits. Have to get 'em from industrial supplier.

Hey Carboy, I was looking at running with discs similar to those, I liked the idea that the one I was looking at was 30cm...ish or so dia and would've fitted near the entire dia of my bucket. But am I right in thinking those babies need a compressor to run?

Worth pointing out with those membrane type diffusers that they are practically uncloggable. To clean all that's required is to ramp up the pressure a few notches and blast them for a few minutes.

The debate on how oxygen gets into the water (via surface and/or diffusion) is interesting and i have no knowledge or answer on it... but of course an opinion.

I don't think aeration can entirely depend on surface exchange otherwise why not just run a bare hose and blow bubbles? Whay are air stones made at all?

I do note in my buckets that the roots have air bubbles lodged and tangled in them constantly, they tend to "cling" to the peripherals before agitation dislodges them to be replaced by others - more so than when I used standard stones which tended to lift my roots to the surface rather than stay with the roots in the water.

And as I noted in my first post - cleanliness. Some water chemist may be able to explain why but I will note my buckets, reservoir, pipes are much, much, cleaner since I went medium pore diffusers. There is almost NIL buildup of any sort (even though I use synthetic nutes there's always been some grime left around the place previously, not as much now). I'd guess from that that cleaner system = cleaner water so maybe that's something that's adding a few pecrcentage points to improvement as well as the more saturated oxygen? - And let me add the answer to that is NOT more agitation leaving less "dead spots". Finer bubble diffusers agitate the water LESS than coarser ones even though they are delivering the same (or even more if you wish) air to the water.

 

[Brazilianfire]

diffusers seem to be the way to go.. im a dwc freak. I love the results. your theory sounds accurate about the smaller bubbles.

 

[turbolaser4528]

now if only we can find some of these diffusers in the us, and not in f*ing australia. anyone find good ones in the us?

 

[oldbubbler]

True I see what you are saying, Id rather have a broth of fine bubbles too, makes more sense to me, just have had much trouble with stones clogging and not producing a lot of bubbles. I have a 35 watt eco plus 3 commercial air pump (70 lph air) in a 30 gallon res, what stones should I use?

Mate, I think with stones you just have to accept they WILL clog. The medium pore ones I'm using are of a much greater quality than standard stones but I'm still accepting that I'll have to replace them down the track, though I'm betting I'm talking a couple/few years as opposed to a couple/few months.

Remember between cycles to clean them - I use watered down OXYPLUS and just soak them overnight and then blast them dry. Of course the OXYPLUS helps break down standard stones but at $3 a pop so what I just replace them every 2nd, 3rd cycle. The quality ones will eventually break down too but them's the breaks.

But no matter what I'd still recommend even standard stones over anything cut/drilled or whatever for the better delivery of oxygen v a few dollars in cost. Even go with bottom of the barrel budget 50c stones and replace them every cycle rather than drilled and sliced pipes IMO.

If you want diffusers that will last near enough for ever you have to look at membrane diffusers such as the ones Carboy noted. Remember these things sit in sh.t pits so if they can handle that they can certainly handle some nutes and ph buffers. All you need to clean them is to blast them with compressed air and they de-clog themselves good as new.

 

[oldbubbler]

now if only we can find some of these diffusers in the us, and not in f*ing australia. anyone find good ones in the us?

Google is your friend. USA is the home of the consumer - anything we can buy in OZ you'll certainly find in the USA and I bet right around the corner somewhere in your home town.

I had to drive 8hr round trip to the supplier for mine.

 

[oldbubbler]

Oh nice.. that never clicked.. I modded my Pan World pump to a DIY needle wheel for my ASM. I may have to order me another pump. My god the amount of air that could be pumped into DWC or any Hydro reservoir would be amazing. I think I like tinkering more than smoking..

Just remember the head-height loss with a skimmer pump. You'll either have to elevate your reservoir to achieve a near level flow (and there's a design challenge) OR get some mother of a pump (and there's a heat challenge).

Love to see it tried though so if you do come back here won't you. As you noted, anyone who's seen the mix in a skimmer chamber would marvel at the thought of water like that being pumped non-stop through your system.

It's not so much aerated water - it's more a 50/50 saturated mix.

 

[Carboy]

Hey Carboy, I was looking at running with discs similar to those, I liked the idea that the one I was looking at was 30cm...ish or so dia and would've fitted near the entire dia of my bucket.
---------------------------------------------
That sounds like it would be great. Those I posted are so damn close to fitting a bucket, but i couldn't make it work right and went another route.
Love to see a link for 'em, if ya got it.
---------------------------------------------
But am I right in thinking those babies need a compressor to run?
---------------------------------------------
Really an air pump is a type of compressor. 50 liter/minute air pumps are what I use. They list their specs in cubic feet. Range 1/2 to 3 cubic feet/minute. 1 cu ft = 28.3 cu liter. So 1/2 cu ft = 14 cu l --- 3 cu ft = 85 cu liter. Off each 50 l/min pump, I run two diffusers. But from the Specs you can see I could run one diffuser or could run three diffusers per air pump.
----------------------------------------------
Worth pointing out with those membrane type diffusers that they are practically uncloggable. To clean all that's required is to ramp up the pressure a few notches and blast them for a few minutes.
----------------------------------------------
HUGE PLUS and great point.
----------------------------------------------
The debate on how oxygen gets into the water (via surface and/or diffusion) is interesting and i have no knowledge or answer on it... but of course an opinion.
----------------------------------------------
There is no debate. Oxygen combines w/ H2O by contact. The more contact the more DO.
----------------------------------------------
I don't think aeration can entirely depend on surface exchange otherwise why not just run a bare hose and blow bubbles? Whay are air stones made at all?
----------------------------------------------
Exactly. It's like champagne --- you want the finest bubbles
----------------------------------------------
I do note in my buckets that the roots have air bubbles lodged and tangled in them constantly, they tend to "cling" to the peripherals before agitation dislodges them to be replaced by others - more so than when I used standard stones which tended to lift my roots to the surface rather than stay with the roots in the water.

And as I noted in my first post - cleanliness. Some water chemist may be able to explain why but I will note my buckets, reservoir, pipes are much, much, cleaner since I went medium pore diffusers. There is almost NIL buildup of any sort (even though I use synthetic nutes there's always been some grime left around the place previously, not as much now). I'd guess from that that cleaner system = cleaner water so maybe that's something that's adding a few pecrcentage points to improvement as well as the more saturated oxygen? - And let me add the answer to that is NOT more agitation leaving less "dead spots". Finer bubble diffusers agitate the water LESS than coarser ones even though they are delivering the same (or even more if you wish) air to the water.

OLDBUBBLER you hit the nail on the head with that paragraph!! In the simplest terms, we are all trying to provide the best environment for what we want. By providing a rich oxygenated water, we are doing that w/ the HUGE (and it could argued, more important) benefit of making a hostile enviro. for what we don't want.

edit: https://usabluebook-onramp.com/docs/images/40.pdf
Mention this in passing before, but this particular link has alot of good info ------ plus pictures !!

 

[Brazilianfire]

Is there any department store that carries low p.s.i. diffusers?

 

[turbolaser4528]

edit: https://usabluebook-onramp.com/docs/images/40.pdf
Mention this in passing before, but this particular link has alot of good info ------ plus pictures !!

those diffusers looks bad ass, I want a couple, but I need one that will hook up to the standard airstone tubing. I don't know how I could hook up an air pump to 3" pvc pipe lol maybe someone can help with that part.

 

[215Z]

I bought a membrane diffuser (tubular not disc shaped) from a pond supply mail order joint up in Washington state.

I do E&F not DWC, I imagine if I went deep water or deep flow i'd use a jacuzzi venturi in-line after the water pump - skip the air pump alltogether.

Watt for watt, a venturi dumps more 02 into your water than any diffuser or paddle - i'll go grab the citation if you need it

 

[Me2]

This is what got me thinking about bubble size in the first place when I was thinking about aero - the small droplet size.

I know we're talking the difference between water (droplets) and air (bubbles) but it got me thinking if micro droplets turbo'd your plants could micro bubbles do similar? Maybe not turbo them so much but give them a few more horses under the hood.

And it does.

I like the thinking and it looks like it should add a few extra horses :wink:
Here`s my take on what may be a limiting factor.
Airstones produce a lot of bubbles but i`m not sure it`d be enough if you directly compare them to the number of droplets generated by a high pressure (75-90psi) aero system.
To get an equal amount of 50 micron air bubbles compared to 50 micron droplets, the airstone will need to generate 2.04 billion bubbles per minute from just 600ml of air.
Is it likely..i`ve no idea, not many airstone come with a spec sheet :wink:

I have a gut feeling it may take a similar air pressure as the aero`s hp water pressure (~75psi) to deliver the same bubble quantity and size in the same time frame.

Definitely worth a go though.