squarepush3r
Well-Known Member
I posted this in another forum, but should find it interesting here also.
So I got a DO meter, to run tests and experiments on how to make the water oxygenated. This applies for aeroponics, bubbleponics, DWC, and most hydro systems. The goal is to get a high amount of oxygen in the water, between 15-30 (super saturation) mg/l score of DO for optimal growth. Here is a normal saturation table, which shows normal saturation values.
http://www.aquatext.com/tables/oxygen.htm
For temperatures of about 70 F, DO saturation is about 9
My first test was to take an empty, clean 18 gallon Tote, and fill it with tap water. Did so, and measured the DO. It showed about 7.1. Then, I inserted an airstone similar to a DWC system, and ran it for several minutes. The results stayed nearly the same, maybe increasing to 7.3 possibly. Next test, I inserted a needle wheel pump into the tote, and ran it for several minutes. Same results as the air stone.
Finally, I ran a test bubbling Ozone (O3) into the tote from a 600mg Ozone Generator. Same results.
So far, all 3 methods applied to the water supply, had little to no effect on increasing the DO levels. I was a bit surprised here.
For my final test, I decided to try this out in a 'real world' situation, into an operating DWC system with plants and nutrients. My current system lacks a chiller hooked up, which will be fixed soon. However, water temps were very high, estimated 80 F. I tested the water while the air stone was running. It showed approximated 7.4, still within a close range of our other 3 tests. Now, I decided to turn the air stone/air pump off, wait a few hours, and see what happens (ie: basically running a DWC system without an airstone, just plan water tank). I came back several hours later, and the results were shocking. With the airstone off for nearly 3 hours, the DO levels showed nearly MAXXED out my meter at 18-20 gm/lt. (my meter only reads from 0-20). So, with the air stone off for several hours, in a live plant environment with nutrients, the oxygen took on nearly double the oxygen saturation rate.
From my hypothesis, the plant roots would 'eat up' the oxygen and the DO levels would be lower after my wait. It turned out the opposite to be true. Now, I will say, I just got my meter and I seem to be operating it correctly, but the calibration might be off, or I may be doing it wrong ... but still these results I really can't come up with an answer to explain them.
My DWC container isn't completely light proof, its possible algae may be increasing the oxygen in the water somehow? I read they decrease the oxygen. Maybe the salinity/temperature is throwing the readings off?
Any comments or questions ? I can run some tests with my meter with hypothetical situation
So I got a DO meter, to run tests and experiments on how to make the water oxygenated. This applies for aeroponics, bubbleponics, DWC, and most hydro systems. The goal is to get a high amount of oxygen in the water, between 15-30 (super saturation) mg/l score of DO for optimal growth. Here is a normal saturation table, which shows normal saturation values.
http://www.aquatext.com/tables/oxygen.htm
For temperatures of about 70 F, DO saturation is about 9
My first test was to take an empty, clean 18 gallon Tote, and fill it with tap water. Did so, and measured the DO. It showed about 7.1. Then, I inserted an airstone similar to a DWC system, and ran it for several minutes. The results stayed nearly the same, maybe increasing to 7.3 possibly. Next test, I inserted a needle wheel pump into the tote, and ran it for several minutes. Same results as the air stone.
Finally, I ran a test bubbling Ozone (O3) into the tote from a 600mg Ozone Generator. Same results.
So far, all 3 methods applied to the water supply, had little to no effect on increasing the DO levels. I was a bit surprised here.
For my final test, I decided to try this out in a 'real world' situation, into an operating DWC system with plants and nutrients. My current system lacks a chiller hooked up, which will be fixed soon. However, water temps were very high, estimated 80 F. I tested the water while the air stone was running. It showed approximated 7.4, still within a close range of our other 3 tests. Now, I decided to turn the air stone/air pump off, wait a few hours, and see what happens (ie: basically running a DWC system without an airstone, just plan water tank). I came back several hours later, and the results were shocking. With the airstone off for nearly 3 hours, the DO levels showed nearly MAXXED out my meter at 18-20 gm/lt. (my meter only reads from 0-20). So, with the air stone off for several hours, in a live plant environment with nutrients, the oxygen took on nearly double the oxygen saturation rate.
From my hypothesis, the plant roots would 'eat up' the oxygen and the DO levels would be lower after my wait. It turned out the opposite to be true. Now, I will say, I just got my meter and I seem to be operating it correctly, but the calibration might be off, or I may be doing it wrong ... but still these results I really can't come up with an answer to explain them.
My DWC container isn't completely light proof, its possible algae may be increasing the oxygen in the water somehow? I read they decrease the oxygen. Maybe the salinity/temperature is throwing the readings off?
Any comments or questions ? I can run some tests with my meter with hypothetical situation
