Could Air Stones Be Doing More Harm Than Good?

[Aktommy]

I'm running a 6000 gph reeflo to power my waterfalls. I just made 1/2" pvc pipes with caps and 3/8 holes for spray nozzles.

 

[FooDoo]

week 8 eye candy

 

[FooDoo]

Came across a link to a study done on lettuce growth at different DO levels

https://www.ncbi.nlm.nih.gov/pubmed/11541573

"There was no significant difference in fresh weight, shoot and root dry weights among the DO concentrations: 2.1 (25% of saturated at 24 degrees C), 4.2 (50%), 8.4 (saturated), and 16.8 (200%) mg/L. The critical DO concentration for vigorous lettuce growth was considered to be lower than 2.1 mg/L. Neither root damage nor delay of shoot growth was observed at any of the studied DO concentrations."

 

[cannabeans]

@FooDoo
Question.. I understand what you have proved about air stones. My question is...
Instead of using an air pump why not use pure oxygen? How fast would the DO levels rise if you were pumping pure oxygen from a tank through your water? I believe I read a comment from someone on here mentioning this..
So now I am curious!

 

[JMcG]

My experience has been very similar to Phats and Foos..
I ditched the air stones in one of my four bangers in all the pods but left just one in the epi , actually just the hose without a stone, which flumes nicely. Probably will remove even that on the next run and just rely on the return line to handle it all!
To help circulate the pods I did add a 45 degree pvc connection into the intake on each pod which angles slightly upwards. This creates just a very gentle swirling effect on the waters surface, keeping it from forming any floaters.
My roots look great and the plants are kickin ass. I do notice that the roots are structured differently, with more fine hairs on the primary's than I've seen before.
Glad you're still here Foo, thanks for the cool tip!

 

[FooDoo]

@FooDoo
Question.. I understand what you have proved about air stones. My question is...
Instead of using an air pump why not use pure oxygen? How fast would the DO levels rise if you were pumping pure oxygen from a tank through your water? I believe I read a comment from someone on here mentioning this..
So now I am curious!

"Why not use pure o2 instead of an air pump. "

Because studies show wether your at 17ppm DO @ 200% saturation or 2 ppm DO @ 25% saturation, the growth stays almost exactly the same.

So the answer is the o2 is just as ineffective as the air pump in terms of increasing plant health and growth rate. Plants don't need high levels of dissolved oxygen AND don't respond to increased levels.

You can get your water to 500 ppm DO with 800% saturation and your plant would grow just as equal as a plant sitting in a cup of standing water (per say)

 

[Aktommy]

Here's a better pic of my jets/waterfalls in 27 gallon totes. I'm still running a chiller and temps are at 68 with room temp at 79

 

[JMcG]

@FooDoo...
Is this your floraduo run?

 

[mandalaman]

Looking awesome @FooDoo

 

[FooDoo]

@FooDoo...
Is this your floraduo run?

yes

 

[FooDoo]

i had to harvest at the end of week 8 due to a mini split malfunction that couldnt be repaired enough to make it the extra week or two.

these are the most massive roots i have ever seen in my entire life. they actually suctioned to the inside of the bucket when i went to lift them out and made a loud slurping sound as they let loose.

***** HANDS DOWN, WITHOUT A DOUBT, AIRSTONES DAMAGE AND RIP APART YOUR ROOT SYSTEMS!! *****

first pic is the front side and second pic is it turned 180 and showing the rear side.

 

[FooDoo]

NO air stones. NO air pumps. TAP water. 73 degree water with basically NO water chiller.

less is more folks. save money, get better results.

 

[justiceman]

i had to harvest at the end of week 8 due to a mini split malfunction that couldnt be repaired enough to make it the extra week or two.

these are the most massive roots i have ever seen in my entire life. they actually suctioned to the inside of the bucket when i went to lift them out and made a loud slurping sound as they let loose.

***** HANDS DOWN, WITHOUT A DOUBT, AIRSTONES DAMAGE AND RIP APART YOUR ROOT SYSTEMS!! *****

first pic is the front side and second pic is it turned 180 and showing the rear side.

hahahahahahaha! Laughed so hard when I read that part. Great job man!

 

[JMcG]

I just chopped plants that ran most of the cycle without air stones in the sites, just one in the epicenter , and one in the rez.
No chiller, never had the need for one yet, temps mid to upper sixties throughout the cycle.
Still on RO tho...
Roots looked great, maybe not as nice as yours FooDoo, but healthy af.

 

[Aktommy]

NO air stones. NO air pumps. TAP water. 73 degree water with basically NO water chiller.

less is more folks. save money, get better results.

Awesome test FooDoo!

 

[JinkysOars]

Finally getting round to trying out this rdwc/undercurrent setup minus the air stones! A bit unsure where to maintain the water level in relation to the net pot! Any opinions?

 

[JMcG]

I like mine within an inch or so off the net pot. I fight low humidity though so that is one reason I stay so close. I don't want to get my medium too wet and invite FG s to the party either....

 

[Aktommy]

Day 18 12/12 no airstones, just waterfalls. Extremely healthy roots and plants, literally the most aggressive growth I've seen since starting RDWC many years ago.

 

[Ignignokt]

Like your results there, @Aktommy. So, do you remember why you used air-stone injection in the past? I know I've seen it over and over as a recommendation, but your results seem to indicate possible shenanigans or poor science. I've been evaluating RDWC for some long time, mostly to evade the intensity required in coco. RDWC is very favorable for automation - I've seen a few examples here that make it compelling. Thanks for sharing the photos - That is the way I like to see them grow, you need great roots to get that level of turgidity ( the uplifted sun leaves ) and a proper nutrient diet. Droopy plants are really unhappy plants, something has them by their nards.

 

[Aktommy]

Like your results there, @Aktommy. So, do you remember why you used air-stone injection in the past? I know I've seen it over and over as a recommendation, but your results seem to indicate possible shenanigans or poor science. I've been evaluating RDWC for some long time, mostly to evade the intensity required in coco. RDWC is very favorable for automation - I've seen a few examples here that make it compelling. Thanks for sharing the photos - That is the way I like to see them grow, you need great roots to get that level of turgidity ( the uplifted sun leaves ) and a proper nutrient diet. Droopy plants are really unhappy plants, something has them by their nards.

My first RDWC build years ago started out with no airstones, as I was following heath robinsons builds and used his designs as inspiration, at the last minute I added the airstones because other RDWC growers were using them. I ran with airstones for the last 4-5 years and now realize that it was a waste of money in both the cost of the stones and the pumps, along with the added heat, electricity and risk of pathogens being pumped into my systems.

These plants look really healthy but honestly it could be other factors contributing to their health. This is a complete rebuild and I'm running CMH 315s instead of HPS bulbs. The plants are loving the spectrum from the CMHs. My roots look healthy as I've ever ran though, and that I'm pretty sure is because of the waterfalls.

Peace