Nate_in_AK said:

I recently switched from 2 x 5 gallon buckets to a 37 gallon tote. I have a 15LPM air pump feeding 4 decent sized stones. I put a drain nozzle at the bottom of the tote and wondered if pouring a little rez water from the drain would work for pH/PPM testing. I found the drain water to have higher PPM than when measured from the top of the rez. Then I found that manually stirring up the rez water resulted in a higher PPM reading as well.

My theories:

• A little sediment is probably normal and I should just take readings from the top of the rez and stop being a troublemaker.
• My air pump + stones are doing an inadequate job of keeping the rez from becoming stagnant and I need an upgraded something here.
• It's the end of the world as we know it.

Now, I figure my first theory is most likely, but would love to hear from others using large totes.

Oh, and I'm just using standard DWC + air stones, nothing else. No drip, no pumps, no quantum entangled vortexes.

Click to expand...

Howdy Nate!

If you are premixing you nutes before you put them in the rez, then #1 shouldn't be an issue (unless you are not waiting for it to dissolve). I would place my money on #2. Although if you have too much agitation your PH will go change (UP) rapidly, at which you turn down the air flow until it steadies out, while still "mixing" the rez. i use two of the 4" dome stones as my primary and i have a small 1 inch in each corner.

Let me know how it goes.....

Happy Growing

I use totes, about that size I run a 790gph air pump to 4 4inch flat stones. The water in my rez looks like its boiling, the higher your rez temp the less ability it has to hold dissolved o2 so you will require me air.
The idea that you can have too much air and it will dissolve the nutes fast imo, so ph corrections can be made quickly. Disolved o2 can increase ionization but rarely modify standing pj so why not. It can increase evaporation which may have an effect on ph, But you need to make aure you seal your system so that all evaporated water can be replaced by the vapor and dripped back to the rez. You need to make as tight of a system as possible.

As far as measurements, the water in your system should have a ton of convection from the air in the stones. No matter where you take a reading after like 5 min everything should have homogenized, if you have adduaquate convection. If it's low you can always add a aquarium pump or upgrade your air system.

As far as the floccution in the tote its prob plant detritus or dead root sediment if you mixed notes right. I mix in my rez everytime never a problem even using dry stuff like maxi grow. The increased water flow will help with dissolving hard to deal with nutes. Just have to learn your system, every one I build.is diff