I am curious about dissolved O2. I suspect I am over aerating (see diagram below) but I want to error on the side of too much aeration to ensure max saturation.
One question is what is the minimum O2 level to support aggressive growth?
I feel like I have more than enough aeration, but I would like to measure the dissolved O2 to validate how much aeration is actually needed. Maybe I can eliminate one of the air pumps.
What have you folks found to be the best way to measure the O2? I see some meters, and titration type test kits for the aquarium hobby. What is the best bang for the buck?
I donât measure dissolved 02 but I keep a ln air pump running 24/7. Allow the return to drop and splash back in the Res. And add h202 once a week which dissolves into oxygen and water. Itâs more than sufficient bro
When I first started growing with DWC I had big 35w air pump going to 4 buckets. While the plants were small everything was fine. As they grew I found 2 males that I pulled and decided to plant a female outside. So at that point I had that 35w pump devoted to one bucket. Wasnât long before I was seeing frequent major down swings in pH. I couldnât figure it. I read that some types of biology could bring pH down so I took steps to mitigate that. My roots were white and my water was clean. Still didnât stop. I was adding pH up every evening and morning. Was lucky enough to come across a post on ICmag I think it was. It was talking about Acid Rain Effect in reservoirs in DWC. From what I recall, as you pump air in there to get dissolved O, youre also pumping CO2 in there and it can add up making the rez acidic. I adjusted the valve on my pump and that fixed my issue. This is purely anecdotal, after my issue was fixed I didnât look any further into the matter but it might be something worth knowing.
I double checked to be sure, the calculator is accurate
After running rdwc for 10+ years with pumps, I strictly roll with a waterfall and itâs perfect.
I never measured the 02, I think heath did. He bought a few gadgets⌠the $$ one were good.
Edit
The solubility calculations give you the saturation point. Whatâs in the water is a mystery.
If thereâs tiny bubbles on the sides of your container, youâve hit saturation.
Youâd really need a D.O. meter to know how much you have⌠Cheapest are around $100 and they only go up from thereâŚ
I do flood and drain, and with 2 to 4 hour intervals between floods, I found I do not need to run any airstone or otherwise to aerate that water. Just the act of flooding the tray for 1 minute every few hours is more than enough for the plants.
I mean⌠I would think all of them are kind of a waste of money. Assuming it works youâll need it all of 5 minutes and then never touch it again
What kind of system are you running again? RDWC? if itâs RDWC Iâd use waterfalls in the buckets and you donât need anything else. The constant churning of the waterfall will fully saturate it all.
You should be able to deduce oxygen levels from checking/smelling the water and looking at the plants. Stale/Old water usually gets a film on the top and doesnât smell good nor âfreshâ.
Yes this, CO2 will combine with water to male carbonic acid. I think this would be the issue you would see long before an issue with too much dissolved oxygen.
My objective is to see if I can reduce the # of air stones and eliminate a pump if I can. Eliminating a pump will save energy, expense, and complexity. I.e. simplify the setup. However, I need to prove to myself that I am reaching saturation in the process.
I really do have a gut feeling that I am currently way into overkill territory.
Is there a way to calculate how many liters per minute of supplemental air are required for a volume of 20 gallons at a flow rate of 500gph?
If your setup is the one pictured above, Iâd say itâs overkill for a 20 gal setup. Hell just one 50w air pump is overkill IMO. And air stones? Chuck 'em. They need replacing every few runs and could cause contamination problems if not cleaned properly. @JoeCrowe showed me his use of a stainless nut with a âTâ and Iâve been rocking that ever since.
