Idea for a DTW Hempy System

I'm sure this has been done before. My idea is to have a Hempy type system that drains to waste the standing water at the bottom of the bucket, and refills via top feed once per day. I've never tried a Hempy before, but one benefit claimed by this system is that whenever you water from the top the standing water at the bottom gets pushed out and new (fresh) water replaces it. This would not be true for the systems I've seen explained online, because as the new water goes in from the top it would mostly drain out of the side hole and much of the stagnate water at the bottom would not be refreshed.

My idea is Instead of a hole about 2 inches from the bottom of the bucket there would be a hole at the very bottom, and tubing would connect this hole to another bucket outside the room. The outside bucket and inside bucket would be at the same level. The outside bucket would have a drain tube connected to it that would normally be closed with a valve. When lights go on the solution is pumped from the top and fills the bottom section. At lights out the bottom section gets drained to waste leaving the roots in nothing but perlite until they are fed again at lights on.

I would use perlite for the bottom section and hydroton or lava rock at the top.

My only problem is how to automate the opening of the valve on the outside bucket to drain the solution.

Any critique of this system would be appreciated.

tilopa said:

.. I've never tried a Hempy before, but one benefit claimed by this system is that whenever you water from the top the standing water at the bottom gets pushed out and new (fresh) water replaces it. This would not be true for the systems I've seen explained online, because as the new water goes in from the top it would mostly drain out of the side hole and much of the stagnate water at the bottom would not be refreshed.

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Like you, I have not tried Hempy....yet. That said....I think you may have part of this wrong. When the new solution is fed in from the top (or bottom for some designs)..it doesn't necessarily displace the existing solution...as replace what has already been used. Thus strengthening what is currently remaining while replenishing the reservoir. At least that's the way I understand it....however it wouldn't be the first time that I was wrong.

Any critique of this system would be appreciated.

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IMHO....one of the best virtues of the Hempy system is that it is so dead set simple. Sure a bottom drain (plug) to occasionally drain the system completely...would be helpful...but..if I am going to run tubes/pipes/hoses outside my room/tent ....plus plug more stuff in that might fail....then I would just go RDWC and get a return for all my risk. Less stuff to go wrong with just a Hempy and it produces PLENTY of herb. Again....just an opinion from someone who's next grow will be a Hempy.

I don't understand what the point would be. I've tried hempy a few times, and what I don't like about it is that you really can't flush your container, so nutes are always accumulating. I prefer DTW myself. I guess your idea would solve the issue I have with hempy, but I just don't understand what would be better about DTW+Hempy vs normal DTW.

indagroove said:

I've tried hempy a few times, and what I don't like about it is that you really can't flush your container, so nutes are always accumulating.

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A bottom plug/drain would allow you to completely drain the "reservoir" along with getting an idea of what and how much your plant is drinking.

I prefer DTW myself.

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Different strokes for different folks. I like the idea of having a small reserve of nutrients for the plant to uptake....more flexibility in when to feed.

Old Toker said:

A bottom plug/drain would allow you to completely drain the "reservoir" along with getting an idea of what and how much your plant is drinking.

Different strokes for different folks. I like the idea of having a small reserve of nutrients for the plant to uptake....more flexibility in when to feed.

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I guess I assumed that you were already going to have the feed automated. One problem I have with hempy is that there are not regular dryback times. It is simple tho, and I've done hempy multiple times but always end up going back to DTW. I have one hempy plant outdoors now, because I can't automate waterings outdoors.

The drain hole is a great addition to hempy, because the one thing that always bothers me is no real ability to flush.

indagroove said:

...but I just don't understand what would be better about DTW+Hempy vs normal DTW.

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The thing I like about Hempy, in concept at least, is that the plants lower roots are always in nutrient solution. I assume that the lower part of the bucket is filled with perlite and nutrient solution and the roots sit in that? So, they can feed whenever, and however much, they want. I consider hempy to be a type of Shallow Water Culture as opposed to a DWC. It's not full-on roots in water, but it is partially. But, like you say, the thing I don't like is not being able to refresh that stagnant water at the bottom regularly.

Though one could do a re-circulating hempy, where the water at the bottom gets flushed back to a main rez and then gets filled by top feed pump. Not sure that idea is better, but in theory it could work well.

My last grow was DTW with coco in 3 gal air-pots. Automated feed 8X daily. Worked fine...but I am in a different situation now and need something that is simpler. Hard to get much simpler than Hempy if you have to grow indoors. The bottom drain is just to satisfy my need to "tinker" with the system and to ensure that the nute mixture is correct. The drain should also help me to determine how often to feed after the roots reach the bottom. I am not sure how much solution the bottom 2 inches of a 5 gal bucket filled with hydroton will hold....but I know that at different stages of development a plant can uptake a lot of water/nutrients and I'd like to make sure that reservoir doesn't get so dry that it can't feed what's needed. Just hypothetical for me at this stage...but eventually I will figure it out.


Good luck Indagroove! Hope all your grows are successful.

can an Automated Ball Valve work in this situation