Venturi Question

[Bill091784]

I'm interested in building a dwc set up. I was thinking about using Venturi injectors instead of air pumps. If I connected a series of tubs together with an injector set up in between each bucket would I have enough pressure throughout the system to have each one operate properly or would I get diminishing returns as I go down the line even if I looped the buckets together?

 

[Papageno]

 

[Papageno]

So I would add that it really depends on the type of DWC you are doing. Technically a strictly DWC does not pump water. So maybe you are taling about an RDWC or an Undercurrent or a Bubble Flow...

However assuming you are talking about say a Bubble Flow I would think adding a venturi at each site external to the bucket right at the inlet would work if designed with enough force. I think I will give it a try myself. The key is you need a good sized water pump. Bad thing is you loose a layer of redundancy. The nice thing about having an air stone and air pump is when the water pump dies the air stone keep the plants from choking. i would think this is a great addition but not something that should preclude using an air pump in any DWC.

 

[Bill091784]

Thanks for the advice. I wasn't able to watch the videos because my internet sucks lol. Luckily I work at an agricultural supply outfit so everything I buy there is nearly at cost so I can get some fairly beefy pumps for a good price along with pretty much everything else needed aside from the ventures which I don't think we sell and air pumps. I think what I want to build is either a rdwc or uc system. I had the system laid out in my head before I heard of either. I was hoping I could get some more advice besides the venturis. I should probably explain what me and my gf want to do with this system. We want to grow fruits and veggies but we don't have a yard to do. We've always been interested in hydroponics and figured with my current job it would be the perfect time to try it out.

O.k. so here what I've envisioned. We want to use low wide tubs that are shaped like a race track. They can hold 10 inches of water and still have a few inches of space to the top edge of the tub. I want to connect each tub end to end, the curved ends I mean with an injector between each tub. Here's where my idea gets most likely not possible. I want to have some pipe go into the reservoir then drop down and double back on itself so the jet of water fires backwards towards the half circle back wall of the rez so the water will be still forced forward because of the curve and hopefully there will still be enough pressure to have a smaller pipe come out of the end of the first 90° down turn that will go above the water line and become a manifold with several jets of Venturi air fortified water firing down in the water surface breaking up the surface so that the water can become even more oxygenated and still have the main backwards turned pipe pushing water from one tub to the next and just have the pump just looping the water around and around. I also want to add a top feed for when the plant are first getting established that I can turn off when the roots finally drop down into the rez with a simple turn valve. There's a few other things I want to do but they're mostly not really for looks but not too necessary to the system.

 

[Papageno]

There are tons of hydro forums out there that are not dedicated to cannabis where you can probably get better advice. Different plants like different environments. If you want to grow veggies then I would take a look at what others are doing to grow the exact same ones you want. Cannabis growers build systems that are hugely overbuilt in order to enable growing monster trees indoors. If you scan the web a short time you will find many indoor growers that have 6 foot tall almost tree like plants in buckets. If you want to grow lettuce and kale and squash you don't need a hydro system designed for a 6 foot tall tree.

Around here that is the kind of advice you will get.

Also the crucial part you are describing is hard to follow as you have a 7 line sentence. can you break down your description or draw it out on paper and post a picture of it? I think what you are describing is ...


1) A Venturi injector between the the reservoirs connecting them in series...Nope that can't work. Watch the first video I posted. He explains how a venturi works decently. Not the best but alright. Basically you must have a high pressure source going into a small opening creating more pressure where the inlet is and then that goes back into a larger pipe or the res to drop the pressure again. The only way to do that how you describe is with sealed high pressure reservoirs.

The right way would be to have a single pump that goes to a manifold and splits to each res. Again like I suggested for the bubble flow have the venturi exterior to the res but right at the res wall. You can pipe the exit of the venturi anyway you want inside the res. like you describe in the 7 line sentence. Then you will need a return line back to your central res that the pump is sourcing from. Basically follow the bubble flow bucket design like I suggested but use the tubs you want. But you can not obviously be continuously pumping in water without an outlet going back to a central res. If you ran a single tub you could do it by running it back in, OR you could have a second manifold where you bring return lines from each of the tubs together and run that to the inlet of the pump but due to variations in pipe restrictions you still could overflow a tub. Using a centralized extra res is the easiest way to deal with water levels, pH, Nutes and full system res changes. If you have a central res like a bubble flow system or a UC system you can just check that, fill that, dump that, and all the tubs will match.

If you want to run different vegies in each tub they may have different nute requirements and all this is not helping. Again ask the right people.