Is aeration necessary in a resevioir when the solution is circulated well?

[cocodreams]

Hey all,

I switched to drain to waste coco a few years ago, for most of my indoor and outdoor MJ and vegetable crops. (I still have quite a few soil projects outside) Even my Native American 3-sisters garden is in hydro.

Some of my watering is automated (usually my MJ) and some I continue to water by hand. For a low tech grow, I find that it uses less nutrient solution overall that some recirculating systems if you factor in reservoir changes. I rarely ever have nutrient deficiency problems in my plants. I add a bit of cal-mag to my nutrient solution from the beginning to prevent the few nutrient problems that coco tends to have.

Here's my question...

I use circulation pumps in all my reservoirs, including my hand-watering solution. I have always used air stones in the reservoir as well mostly out of habit. With all that circulation of the solution, are air stones really necessary (in drain to waste)?

 

[Ebb n Flo]

currently i work with an ebb n flow system using canna nutrients and canna says not to put a bubble/air stone in the reservoir. so i didnt and i've never had a problem... as long as the nutrients are constantly circulating i think it would be fine. i really dont see how on a drain to waste system that the bubble stones would do much of anything.

 

[Prefontaine]

The point of having a bubbler in your reservoir is to provide oxygen to the roots, if you are running an ebb and flow this is not needed, Deep water cultures require the bubbles,

 

[Ebb n Flo]

agreed but still he's not technically running a deep water culture system... he running a drain to waste in which the water is constantly moving. wouldnt the current provide sufficient oxygen for the root system? i understand why dwc needs bubble stones.. i run a dwc as well! however in a dwc the water just sits there and isnt mobile like a drain to waste is!

 

[Prefontaine]

i dont see anywhere that he is saying he doesn not recirculate his nutrient solution, also if you have a continous stream of water over your roots, you are not doing an ebb and flow system, you are doing a straight flow system, roots have to breathe, and ebb and flow system you use pumps on timers to provide water for a while, then drain to allow the roots to breathe,

The water being mobile has nothing to with it, I can stick a water pump in a DWC bucket and watch my plants drown, the roots need both air and water, using a bubbler in any reservoir will increase the oxygenation of your water, but so will atomizing the water as it is poured into the pot, or a million other ways,

The point is a bubbler is not necessary in an ebb and flow system, and if you are not recirculating your nutrients and just "Drain to waste" your being stupid and pouring out half the nutes before they get used.

so why are you arguing?

 

[cocodreams]

I'm doing drain to waste, so the nutrients are not recycled.

Most people assume that huge amounts of nutrient solution are wasted during drain to waste. Unless the system is designed poorly, this is not true.

Coco holds a high quantity of fluid. In the type of system I use, the medium is watered once a day, until the nutrient solution just barely trickles out the bottom. In this way, only a minimal amount of nutrient solution is lost per day. The remainder of the solution stays in the coco, waiting to be absorbed by the plants.

A comparable ebb and flow system with reservoir changes every two weeks would use more water. It all depends on which type of setup you use, but in my experience, I use less nutrient solution with drain to waste. My plants are brilliantly green throughout their entire life cycle.

 

[Lucius Vorenus]

Anyone else not running their recirc pump constantly? I am thinking about switching to this method and just turning it on twice a day for an hour to save heat on the rez. Very hot climate here.

 

[Al B. Fuct]

currently i work with an ebb n flow system using canna nutrients and canna says not to put a bubble/air stone in the reservoir. so i didnt and i've never had a problem... as long as the nutrients are constantly circulating i think it would be fine. i really dont see how on a drain to waste system that the bubble stones would do much of anything.

I've been through Canna's 'Canna Aqua' info file and I do not find any recommendation against forced aeration, only a note indicating that aeration may raise nute soln pH.

If you're using a high-moisture retention medium like rockwool or to some degree, Fytocell, in a flood & drain system, forced nute soln aeration may account for a significant amount of oxygenation to the roots, though the drainback of nute solns after flooding does draw in quite a lot of fresh air at well. In hand-watering applications, if you're going to keep a container of mixed nute soln around for more than about 3 days, an air stone is a good idea.