RDWC - DWC - Need opinion on safe DO saturation range

[JP23]

Insuring minimal safe oxygenation 24/7 throughout a growing season is vitally important and can be difficult and stressful for the grower and the root balls when the grower fails to insure enough dissolved oxygen in the res water.
DO question for an expert hydro grower - What do you think or know that is the optimal safe DO Saturation range necessary to keep plants and Bennies healthy so they do not suffocate?
Dead and decaying root balls do not encourage fungal outbreaks and fungal colonization so they say.

Thanks

 

[DukeO]

The DO is going to change with the water temp.

If your running a chiller it is easier to keep it up.

I don't use one because I run DWC buckets.

I use GH Daul Diaphragms pumps to run up to 4 5al buckets. So about 10gal of water with temps between 72 and 80f with no issues using tap water nutes and z7 water treatment.

I don't have a DO meter. But my roots are white and my leaves are green..

About 1 watt of pump power to 1 gal of water is what a lot of folks use to judge how big a pump to get.

Just remember that piston pumps put out a lot more heat into the air/water.

 

[DukeO]

So for any giving water temp there is a max DO. At 68f it peaks at about 9ppm at sea level.

So if you want more then that you would have to put it under pressure and if you live at a higher elevation it will hold less DO

Most of us shoot to max out at whatever temp we grow at..

 

[DukeO]

(DETERMINING PERCENT SATURATION THE "QUICK AND EASY" METHOD) % means very little without the temp being in the right range.

% means of the max DO. But the temp is the biggest factor for most of us and ppm and temp means more then %.

They give you the max DO.

You can be at 100% DO and your plant could die from lack of oxygen if the water is not at the right temp.

 

[Rider509]

In order to discuss this we have to accept some generalities as there is no definitive study on the LC50 of low levels of dissolved oxygen in hydroponically grown cannabis. Believe me, I tried finding something, anything, scientifically definitive. Therefore, the following is an extrapolation of information.

Generally, hydroponically grown cannabis is grown in solution temperatures ranging from 15.5C to 24C. Empirical evidence indicates that 18C is optimal.

Numerous scientific studies indicate that at DO concentrations of less than 3ppm many aquatic life forms begin to show degradation of viability, and that the LC50 for these organisms is in the range of 1.5ppm. If we want to establish a "safe range" below which we do not want our oxygen levels to drop then we can posit that we should keep the DO above 3ppm.

It follows then that the safe range for dissolved oxygen is generally above 30 to 35 percent saturation dependent upon temperature.

We don't EVEN want to get into how the presence of dissolved solids affects oxygen saturation!

And no, I didn't copy and paste this! This shit is from my own efforts in answering your question, JP23. I hope it helps!