has anyone done a study on ROOTS??

fatman7574 said:

Actually it is the increased flow of water with DO reaching the root masses inner roots due to circulation from aggressive air they like because it causes seperation and movement of the roots. They couldnt really care less about the bubbles them selves. It takes very large bubbles or heavy circulation to cause enough surface turbulation to assure the water is saturated with DO. When you consider that a DWC should have circulation something like 50 to 60 times its gallonage per hour were talking a 24 gallon reservoir using a minimum of 1200 gph to 1500 gph for just a single reservoir. Double that if growing large plants with large root masses.

If depending on bubbles it takes a lot of big bubbles to get the roots seperated enough that good water flow can make it to the inside of the root mass. But, the roots could care less one way or the other how that is done, pump or air. with really god circulation the addition of air bubbles is realy a waste of money is all unless there is no surafce area for air exchange then small bubbles along with circulations should be used. Really though any DWC with a single reservoir is a poor design. It is very, very simple to run a DWC with very high DO and without root rot with an extra reservoir if the second reservoir contains no plants. Simply use it as another nutrient reservoir that is actually kept turbulent with pump action and use a venuri valve to draw air into the pump intake that is fed water by the other tank. Then pump this water at a high velocity into the reservoir with the plants. As long as you stop just short of shredding the roots with the pumped water full of very small bubbles you will then have a good DWC. Picture rapids on a river. That is what a DWC reservoir should look like.

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fatman7574 said:

Retailers are actually selling multiple reservoir DWC units such as this now. Not cheap. These are starting to get closer to good but they are under pumping and using too much air instead. They need to get rid of the punky Danner pump(s) and use a couple good Reeflo pumps or some Iwakis. Replacethe bogus airstones and air pumps with a few ventuiris or a large needle wheel pump. Yes there are better units that are DIY but they are on other sites not this one.

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pftek said:

can you link us to one of these that you speak of? i'm sure we can DIY or something. DWCs are simple and cheap to make.

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