I have a Dissolved Oxygen meter

[Pipedream]

Yes, I too would like to see how a standard 1" airstone compares to just an open "T" fitting in a 1 Gallon bucket filled with either Distilled or RO water.

Two completely different containers of water should be utilized. Both should be well cleaned prior to the test, and the water should come from the same source and added to the buckets slowly with as little agitation as possible. The same air pump and hose should used for both tests. Record results prior to air being added, at 1 minute post, 2 minutes post, 5 minutes post, 10 minutes post, and 30 minutes post. Then remove the air source and remeasure after 5 minutes and again after 10 minutes.

This easily done test will tell us not only how much DO is added with each method, but if there is any difference in how well it is dissolved and therefore how long it will stay in suspenssion.

Post it here or PM me with results and pic's for proof of testing method, and I'll send you your choice of a nice bud or some pure Jamaican Sativa seeds as a thank you.

Pipedream

 

[mace_ecam]

Air stone vs no air stone would be great - have fun!

i second that, don't forget to mention the wattage used for powerheads vs wattage used for air pumps
apart from that i think you'll find that if the DO ppm's don't fall under 4ppm everything is gonna be dandy, if it goes lower, trouble starts

 

[Guest]

Ditto on the interest in seeing how fast the DO ramps up using different methods from when the pump gets turned on. Like I said before...I'd like to see how fast water loses DO. I don't think studying at different temps is that critical as I'm pretty sure you could compensate through calculations but noting at what temp the reading was taken is important.

 

[gmanwho]

Sauce: but what i dont think you get, is the cap of the max amount of o2 would be 4 times more with straight o2 input. remember the meter is reading only "DO" not the nitrogen or co2 molecules.

the cap would be 400% more



ok, say you take 1 oz of water.

just say you are only able to add 100 air bubbbles to that 1 oz of water before it hits its max air saturation point.

using outside air, only 21 air bubbles are oxygen, 78 nitrogen and 1 other out of the 100 possible that you could fit into that 1 oz of water.

take 92% oxygen output, now you have 92 oxygen bubbles out of 100 injected into the water.


By any means i dont think this experiment should be ruled out.I mean for all we know creating this much o2 in the water could be harmfull, or it could be a serious growth inhibitor.

Just have to get the equipment. In due time my friends, ....in due time.

Mace: if you worry about powerhead or pump wattage used to drive the airstones. Put a venturi on your water pump intake side. Your already using the power to run the water pump for the system, hell even use an airstone to diffuse the air intaked thru the venturi.

 

[snoofer4]

I'd like to see the difference between low pressure and high pressure aero systems.

The question is this: is it worth it DO-wize to go for full (ie. high pressure misters with high pressure pump) aero, or is low pressure (ie. spraying water on the roots with el cheapo magdrive pumps) adequate. All things being equal, of course (ie. water temp the same).

 

[mace_ecam]

Hi gmanwho,

a very comprehensive explanation of the partial pressure law, very nice!

The reason i was asking about wattage was to have a scale to compare between airpumps/airstones and powerheads.
I agree that the venturi point would put bubbles in the water, however i was wondering what the dif in DO between bubbles and water movement is.

much respect,

mace

 

[icough2getoff]

I bet you're almost sorry you asked this question unless you take up Pipedream on his bud/seed offer. I would like to cast another vote for airstone VS powerhead moving the water around on the surface. Also airstone VS just a brass T or no airstone would be very interesting also.

Damn I would go crazy if I had one of those meters to test with.

 

[Sauce]

Sauce: but what i dont think you get, is the cap of the max amount of o2 would be 4 times more with straight o2 input. remember the meter is reading only "DO" not the nitrogen or co2 molecules.

Well the o2 would in theory dissolve into the water faster since there's a lot more of it, however the cap will not change. For example if the water can hold 5ppm of o2 at a given temp, just because you inject pure o2 into the water doesn't mean the o2 cap is going to be over 5ppm.

The DO cap is a measure of how much o2 can be dissolved, not how much gas can be dissolved. Pure o2 would not change this cap.

And for LP aero vs. HP aero, I think the droplet size is going to be the major difference, not the DO. High pressure aero systems are usually designed with the correct sprayers to spray at the correct micron size where water can pass directly through the permeable membrane on the roots. With LP systems, the water droplet size will be larger, making the absorption slower. In theory, smaller droplets should pick up more o2 going through the air. Still an interesting experiment, but I think doing it correctly with all the variables thought of would be hard.

 

[Neptune]

can we get some info already or what?

all suggestions, no substance.

 

[gmanwho]

sauce: In theory i was hoping that the max of the said 5ppm would increase drastically if straight o2 was applied. Just was odd to read the charts, come with the conclusion that they where only able to achieve that max DO at given temp with outside air.

then to think "hey they didnt specify if they used pure 02 verses outside air, could straight o2 increase this amount of DO in the water"

owell, was a thought. Maybe the experiment one day could logged.

Now i guess like neptune said, wheres some data?

 

[mace_ecam]

gmanwho is completely right, with plain air, there is only so much O2 to dissolve at a given temp and pressure.

Henry's law and the partial pressure law should be interesting to investigate

In plain english it means the restricting factors for dissolving O2 in water are:
- pressure (a powerhead has an advantage here )
- the amount of O2 in the gas (plain air or high O2 concentration)
- temp

peace,

mace

 

[RM - aquagrower]

just for the record

just for the record

you are using a plant in the bucket/tub for these experiments, right? here's why i ask:

as has been said, water has a max saturation (of DO) at a given temp and altitude.

as we know, surface disturbance increases DO levels, so just the act of filling a bucket/tub should max out the DO levels.

now, someone correct me if i'm wrong, but once the water has reached this max sat point, that DO level should remain constant until some DO is consumed. DO consumers could include fish, plants, algie, or bio activity.

that said, seems to me that the first tests shouls be to find some base lines:

1) find the max sat point of your water, at your altitude, using that meter

then

2) without using any means of "O2ing", stick a plant in the bucket and find the "rate of consumption" for given plant.

once you've got those 2 baselines, it should be pretty easy to test how fast the DO levels rise back to the max (with the plant in the bucket), using different methods.

the ones i'd personally like to see are:

1) airstones vs. open airline

2) small air pump vs. big air pump

3) powerhead w/ venturi vs. powerhead w/o

4) big powerhead vs. small powerhead

if ya don't have a plant to use in these experiments, i would think some cheap (feeder) goldfish would work. only variable using fish would be potential surface disturbence (and thus O2ing) the water by the fish themselves.

 

[Guest]

now, someone correct me if i'm wrong, but once the water has reached this max sat point, that DO level should remain constant until some DO is consumed. DO consumers could include fish, plants, algie, or bio activity.

I worked with an organic chemist years back and he told me O2 will slowly be replaced by CO2 in standing water. In a recent conversation, a solid rep mod on another site was talking about the pH of distilled and RO water and mentioned this gas exchange affecting pH. That's one of the reasons I've asked for this test here...to verify if this is the case and if so how quickly does this exchange occur and at what point does it stabilize.

 

[ShroomDr]

So... Have you done any tests

So... Have you done any tests

This thread is over 48 hours old, have any test been done?

 

[breeder]

Lot of idea's...nice
off topic:....ShroomDR, that is the nicest backside of a women I think I ever saw! I'm always looking at that ass! I can't help myself!
Anyway I'd like to put my vote in for the open ended vs. airstone.



.....love that ass!

 

[morgancola]

This thread is over 48 hours old, have any test been done?

I did do some testing, about 3 hours worth. I guess Im not patient or dont have enough free time to accomplish all you guys ask. I did do one bucket .. But, I think I need to start at a higher temp. I started at 58 degrees. My friends house is cold.. Anyway,Im guessing that at 58 the O2 is about as high as its gonna get. Or close to it.
I did notice, at least in this one test that an open airline with lots of air going through it DID increase DO in the bucket after about 5-10 minutes where a 6" airstone did NOT increase DO after more than 15 minutes. Ill try again today with some warmer water with hopefully less DO in it. Im using TAP water for now.. Letting it set for a few.. Gimme more ideas. Temp to start with?

The airstone vs open airline is crazy. They do totally different things. The open airline is like a wave generator with big peaks jumping like 3 inches to popping out of the bucket. Smaller bubbles look killer makeing a bubble storm but all the little popping bubbles create little jumping water droplets, alot more so than the wavelike action of no stone.. H,mm,mmmmmmm Im thinking in a basic DWC setup that smaller bubbles prolly benefit the roots with more moisture.

Discuss.......

 

[clowntown]

Wow, so with current data it appears that the open airline aerates the water noticably better than an airstone?

 

[eyeoftruth]

nature H t/o zero

 

[clowntown]

What?

 

[morgancola]

Wow, so with current data it appears that the open airline aerates the water noticably better than an airstone?

At 58 degrees yes, the meter showed an increase of DO with no stone VS airstone.


Maybe today at 75 degrees?