Med pressure Aero

So a few months ago I got permission from the wife to grow a couple plants. I rounded up to 3 and began researching hydro/aero like a madman. I decided upon aero and began testing pumps & misters. If I had only found treefarmers 117 page thread. I'd likely be broke if I had. I must have tried 6 sump pumps before I figured out that I needed a diaphram pump. I got the pump, found some sweet misters and started slappin it together. I believe my design to be unique. Although I really wanted a high pressure system and fancy relay on/off action, I was running out of cash and settled for less. I made a short vid going over my system and would like to get some feedback from some of the pros on this site. I'm glad I built it w/o too much outside influence on design, but now that it's done I wanna know if there are things I can do to improve it. Not that it's under-performing. I'm 2 weeks into a grow, and have some really nice lookin white fishbones. I'm cycling the pump 15 mins on, 15 mins off. That's the most I'm comfortable cycling the pump until I step up my game and get an accumulator. I'm doing my best to go through the 117 page thread on treefarmers system, but damn. That's alot of information. Here's a url to my vid.

http://www.youtube.com/watch?v=lBTpVrVDqgY

Hope you enjoy, and look forward to getting some feedback.

Looks pretty good to me I've only done soil so I can't give much feedback. I'm interested in the outcome though all the same.

Cool. I just got one set up a while ago too, except in one of those IBC crates. I used an accumulator and solenoid, with the piping horizontal and misters pointing up. I was hoping it would eliminate dripping and make sure any air is expelled for an instant shut off. I got dripping anyway though. I believe the air was being trapped in the fittings, because they have a larger inside diameter than the PVC. Just something to keep in mind if you rebuild for an accumulator. I think the only real solution is an antidrip valve that turns on and off at a certain pressure like the netafims/DAN foggers have. When/If you go the accumulator route, make sure you put a lot aside for the project... it adds up really fast and there are always things you didn't expect to happen.

I didn't see a filter. If you don't have one, you'll want one, especially with recirculation.

I like the setup. Do you wait until the plants get big enough that the roots would drop through the hydroton before putting them in? Or do the misters get the hydroton wet enough that you can put clones right into it?

Two very good questions. There is a mesh filter on the intake. It's not so easy to access. My bad. The good thing about my nozzles is that the oriface is actually rather large. I'm surprised they make such a good mist. They were like a dollar a piece at home depot. The hydroton does get pretty wet, but next time I will run a dripper on top until the roots break through the net pots. I had pretty slow growth the first week, as you pointed out, the roots weren't getting enough contact. Once the roots broke through, growth has been incredible. Noticable every day. It's probably gonna be awhile before I step up to a accumulator solenoid setup. I'll see if I can come close to my goals with this setup. I'd really like to see 1lb per plant one of these days. People seem to laugh at me when I say that though. Do you have any pics/vid of your setup? Sounds like one that is worthy of aeroponic name.

Cool. I'll have to see if I can find them next time I'm at home depot. These ones that I'm using clog if you look at them wrong. They do clean out easy enough though.

I forgot to ask... your pump has a bypass right? Or do you use a pressure relief valve or something else to keep the pressure under control?

Here's a few pics, they aren't really detailed, but you get the idea. I'm lazy and don't have the backup pump attached yet. It'll go in before that bottom check valve and will be controlled by the bottom pressure switch. The primary (110vac) pump switch is set for 43-70 psi. The backup (12vdc) pump switch is set for 40-60. The timer and solenoid run off the deep cycle.

The pressure tank is pretty small, but it still stores enough that the pump only comes once every 2-3 hours depending on what timing I'm using and whether or not I closed off the rear set of misters. I figured this would be the learning experience and I'd probably rebuild it later.

Ignore the messy piping in the bottom of the tank... that was an experiment to see if the pipe was holding pressure and causing the misters to piss streams of water on shutdown. It's not. There's air trapped in the fittings.

I don't know why I drilled so many holes in the top. I'm not even using 75% of them. I might just start growing veggies in all the extra space. I'm building something separate for flowering, but I've been too busy lately to get moving on it.

The pump has one of those pressure switches on it. I use a valve to re-circ back into the res giving me complete adjustment over pressure. If I close off the re-circ valve completly, the pump does this fast cycle thing that is really annoying. Oh well. I can't get everything perfect on my first time. I'm feeling pretty good overall with everything. My clones have done amazing. Just gotta keep em happy for a couple more months.

So I thought I'd include a little more about what I have going on here, as I'm not really getting much feedback. I'm using H&G Aqua flakes A&B, root excelerator, hydrozyme and some silica that I'm not to use til flower? It's all new to me. I'm on 400 watt MH, and plan to go to 600 HPS for flower. My ppms are sittin around 750 on 2.5 week old clones. I was scared to go that high, but the guy I got the clones from said to do it, and it hasn't caused any probs. The strain is sensi star. Some of the fan leaves are already getting to be hand sized. The one on the right is about 6" tall. Unfortunatly the clones I got were in pretty bad shape. Something about sulfur treatment gone wrong. The far left plant didn't make it, and the middle as you can see got pretty far behind. Can I cut a clone from the healthy plant, and get in to make this flower cycle? I realize that I wanna keep these things roughly the same height, but that might be challenging for a rookie like myself. Hoping to get some expert advice. Thanks!

Mike Young said:

Just gotta keep em happy for a couple more months.

Click to expand...

Haha, yea that's the trick

I can't really help with any grow advice, I'm pretty new to this too. I can make a hardware suggestion to improve your bypass a little. Here is a pressure relief valve meant for bypass duty. The nice part is that there aren't any wetted metal parts (the spring is coated). I accidentally bought one as a pressure relief valve and didn't notice the "some bypass may occur" part of the description, so it was a bad choice for my need. It lets a small bit leak through at all times, which wouldn't be an issue for your use.

http://www.drillspot.com/products/70711/Dayton_3300-0015-10_Pressure_Relief_Valve

Deximus. What do you mean when you say the timer & switch run off the deep cycle? Your pump goes through a check valve, into the pressure switch then to accumulator. What is the purpose of the switch? couldn't you just fill the accumulator and let the pumps pressure switch decide when to stop? Also, is there an electronic valve after the accumulator to control your mist times?

You're correct, the switches are technically unnecessary. I just don't trust the ones built into the pump. Also, these are more flexible with setting the on/off pressures. They also have a low pressure cut off. That means that if the pressure goes below a certain amount (around 10 psi) it will turn off the pump. That way, if something catastrophic happens to the plumbing, it won't pump my entire reservoir onto the floor (and continue running dry after that).

When I said deep cycle I meant the deep cycle battery sitting on the shelf, sorry. The label was facing backwards so it probably wasn't obvious what it was. The timer, solenoid, and backup pump are connected to the deep cycle. That way, I'm safe in case of a power out. With just the timer and solenoid connected, it'll run for months before I have to charge the battery. I'll eventually get a battery tender. With the backup pump operating, the battery might last a few days.

Yea, there's a solenoid controlling the misters, it's hiding up next to the crate. My timer is pretty ghetto. I just couldn't justify the $70-80 to buy one when I know it's just a watch crystal (hopefully) and handful of logic ICs. This one was just a prototype. When I transfer it onto perfboard it'll be in a nice box with a pair of rotary switches for setting the on/off times.

I've got an idea for you, don't know if it will work or not though. I've got two unknown strains in veg right now. One is growing much faster than the other. I let the one grow about twice as tall and then topped it (the top was about 6" after I cut it and I left about 5" on the bottom). Then I put the top in the cloner and it's got root nubs now. Don't know if it will catch up in time. You'll end up with two or more main colas on the one you top though.

Wow! I don't think I'm qualified to make my own timer. I looked into what they call a 555 timer built w/parts from radio shack. It looked out of my rhelm. I assume what you have there is pretty similar? I plan to also use a battery w/ac inverter to run my pump in the event of power loss. I really don't lose power very often. Does your system sense when the power is off, and switch to battery automatically?

I may top, or take a healthy clone for the cloner. I made a scrog net the other day that I'm not sure if I'm gonna use or not. I figured I could strech out the veg doin a scrog, and make for a more even canopy... The only thing stopping me is that once I start weaving stems, I can no longer lift the pot out to spy on the roots. I may have to forego the scrog until I can see what the roots are going to do throughout the grow. I don't want them blocking up the misters, or drain, etc...

When I first stared researching all of this, I heard many horror stories of people flooding their house/basement/garage ect. That would really suck. I've been pretty lucky so far, as I had one fitting that would drip 5-10 times per day (hence little red frisbee in video). I was worried it would get bigger and cut it out & re-did it. I can see where the extra time & money on the switch could pay off bigtime!

The backup is set to come on at 40psi. The main comes on at 43psi. When everything is working normally, the backup pump never has the chance to come on because the main comes on first. If anything prevents the main from starting at 43psi (no power, pump dies, switch dies, etc), the backup will kick on after a few more cycles when the pressure drops to 40psi. The backup doesn't really need to know the power failed, only that the system is below the pressure that I expected the main pump to kick on at.

Good plan. I'd definitely keep access to the plumbing and roots too, especially for the first run. Besides, that way you can take pics for us

I'm not overly worried about even needing the backup... but what can go wrong will. Always. It seems like every time I didn't take precautions against something I imagined going wrong, it did. Of course, after I take the precautions, nothing happens. Hah.

Good thread, glad I found it - for some reason decided on a whim to convert my DIY Coliseum (pic below) to HP aero from its previous LP aero/NFT, and have about a week to get it setup and running..........

A couple of questions/links:

1) Deximus, why do you have your filter after the pump and accumulator? I'm thinking I'm gonna put mine first in sequence, right next to the feed from my reservoir.
2) Why such low pressure? I'm going to be running in the 115-140PSI range - is there any reason you don't go to a higher pressure? Not asking that to be "snobbbish" (my equipment won't even be here for a day or two, and then I have a week to get setup before my clones go in my system), but I'm truly curious - seems like no one really runs >100PSI online, and that's what I thought we were shooting for?
3) Like you, I have (4) 12V solenoids and a 12V timer (http://instrumentation-central.com/ATC/422.pdf) on the way, but there's a month lag time for the timer, so I ordered 4 110V solenoids which I'll use with my CAP super short cycle timer in the meantime.
4) 4.4 gallon accumulator, max PSI of 150.
5) Shurflo pump (http://www.steam-brite.com/store/shurflo-viton-seals-p-4296.html) - pressure switches on at 115PSI, and cuts off at 140PSI.
6) 30 of the white misters (two per column, obviously) (http://cloudtops.com/misting_systems_misting_nozzles/mistingnozzles.php)
7) A shitload of John Guest fittings

That's about it; just wanted to say "hi" and talk to as many HP aero cats as possible while I put this together........

That's a very ambitious lookin setup ya got goin on there. Not speakin for dex, but I don't need more than 45psi on my setup (12 misters). I am certainly interested in seeing your project come together. Be sure to take more pictures, or video.

Is 2 misters per column enough? I would think 1 per plant...

Here's a video from a couple of months ago when I first set it up.........it's changed many times since then, until ultimately now being converted to HP aero.

My understanding was the higher the pressure the finer the mist, no?

And from a guy I talked to at another site, he said a mister per plant would actually be counterproductive because of gravity and all that jazz...........while it'd be cool to get the white fishbone HP roots, that's not why I'm converting - I want a lower electric solution (current 1/6HP pump burns up 600 watts and runs 25% of the time, vs. my new pump which consumes 100 watts and will run for a minute or two every hour - also can get rid of my chiller with a DTW aero setup, saving me another couple of hundred watts an hour) and also the simplicity of a drain to waste setup.

http://www.youtube.com/watch?v=oLsQGDcTevs

I can't wait to see how it comes along. Just read through 15 or so pages of heaths crazy ass system. Damn! That guy's got some skills. Your setup isn't too far behind. I wish I could go that big. My woman is SUPER paranoid, and it took a very long time to convince her to let me grow a few. My plan is to grow em as big and healthy as possible, and I can't wait to re-build. I'll certainly be looking at what you & dex are doing for the future.

Quick question on the DTW? It obviously would be bad on my setup, as I spray far too much water... But does the cost of nutes come into play with that? I'm sure the plants love a fresh meal every feeding, but it seems like it could still be recycled.

Actually, any *reasonably* tuned in drain to waste uses less water and nutes than a recirculating system (assuming the person does reservoir changes in the recirculating system).

And HP aero requires a miniscule amount of nutes because of the efficiency with which the roots uptake said nutes..........you can burn full-sized plants at 500PPMs, which is where I currently veg clones at.........so no, I'm planning on saving both water and nutes when I switch.

When properly done, HP aero is the cheapest system around, both in terms of electricity usage and nute/water consumption.

I'm the kind of person who will design something to such excruciating detail that nothing ever gets built. I started with a lower pressure because it made things simpler and forced me to actually start building the thing instead of worrying about the minutia. I didn't know how the misters were going to behave, how much space they would fill, how easily they would clog... I read treegrower's thread and found that these cheapy misters were used with success, so instead of starting out with the unknown and a larger cash outlay, I just used what other people already have. I'm changing things up for flowering now that I've got a better grasp on what to expect.

I wanted the filter just before the misters to reduce the chance of clogging. I'm using well water, so calcium and nute precipitates are a bit of a problem. I didn't want any precipitates built up in the plumbing on the pressure side to make it to the misters. I also have a filter for keeping larger debris out of the pump on the end of the tube that draws from the reservoir.

One problem you may run into is developing the mist. It needs some room to develop. When I was testing mine out, I had to keep my hand about 15" away or it would get soaked instantly by the spray. Higher pressure of course reduces this distance, but it still may be a problem for you.

Another problem you may run into is dripping. When you have two misters at different heights and the pressure is off, the top one is going to suck air while the bottom is going to drip. The orifice might be small enough to prevent this though, I don't know. I know it was going to be a problem for me. That's why I designed my chamber with the misters pointing up and leveled (see one of the pics I posted earlier). If there was so much as a 1/4" difference on one side, the low side would drip and the high side would suck air. If you're using separate solenoid/plumbing circuits for each height, you might be OK.

Also, if you want your on/off times to mean anything, don't use a flexible tubing between the solenoid and the misters. That stuff accumulates pressure like crazy, and will make your misters piss low pressure streams for seconds after your solenoid shuts off. Accumulated air in the lines will do the same thing.

I'm not trying to crap on your plan... just letting you know some problems I ran into in case you haven't thought of them.

I'm upping the pressure for flowering. I'll probably run it 63-90 psi. The frame is going to be PVC. The bottom section will be covered in silkscreen, which will allow drainage but not allow the roots to grow through. I'll either train the roots towards the center, or around in a spiral. The mister will drop in from the middle (I didn't make the diagram that detailed). I have limited vertical space, so I don't have room to let the roots hang (especially for tall plants). The sides will be just opaque plastic, so I can move it and have full access to the roots. For the first run, I'm just going to dig a pit and plastic it for the bottom. Might do concrete later.

The vertical poles are for a screen. I'm thinking of having the screen 20" from the center. I don't know if that's too close/far for a single 1000w bulb in the middle though. I've never grown vertical. Any thoughts? Would I be better at 24"?

I think I'm going to go with netafim foggers. Despite their claim of 85 micron average drop size, lab testing seemed to prove that 85 is about the maximum it produces. Not sure of the orientation yet. I'm thinking of either dropping two in the middle for an 8-way or four around the outside pointing in. I'll end up doing 4 around the outside if having two in the middle deposits too much water on the outside walls.

Good post bro, thanks for that.........as far as your question about your radius with a 1K, if using a single 1K i'd go with 20".........if using two or more stacked on top of each other, than I'd bump it out a little further, bout 24".

Yes, there are 30 misters for 15 columns, so two per column, and each "level" (of the two levels) will have two solenoids at either end, so the pressure will meet in the middle - eac tube will have its misters at the same height.

As far as flexible tubing, what are you speaking of? Like cheapo hydro store tubing? I've got 100' of this here, and I've seen others (Treegrower as well) have success with it - it's rated up to 230PSI, so I'm not too worried about it flexing that much.

Ahhh, gotcha on your filter placement.............I've actually been wondering if I *need* to use my R/O filter for this project, because my water comes out the tap at about 150PPMs..........not great but not killer - that being said, without a mister per plant I probably will have to run more water than "optimal" to ensure that every plant at least gets fed in some way (be it LP aero or NFT), so I'll be going through a decent amount of water per day - would prefer to not have to triple that by using my RO filter (waste water is a bitch), but I'll suck it up if I need to.

Was also planning on shooting my nozzles horizontally (into the other side of the tube) to give the mist as much time to form as possible before it drifts over the roots.

I actually just ordered a pressure switch (100-125) because I didn't wanna max my system out and run at 140PSI, which is just about the max for the solenoids, pump, and accumulator............125PSI gives me some fudge room, and I've also heard that the pump pressure switches "drift" a good deal and can not be trusted too much.

Have everything but the pump and accumulator (should be here any day), so I'm planning to get to building it this weekend (some clones are already showing roots, so it's kind of a race against time at this point).

Cool. I'm going to use more of an open netting I think, so maybe I'll set it at 24" and expect the plants to grow through it. It's mainly there for support.

I did an experiment with pex tubing and got some run-on with a mister. The rest I only know from reading about others, probably using (gah) vinyl. Since the misters have such a low flow, it doesn't take much expansion of the tubing to make them run on. I've had bigger problems with trapped air than tube expansion. You'll have to try and see I guess. I gave up and will be using anti-drip valves from now on.

I don't own a PPM meter yet. I'm afraid to see just how much calcium is in my well water. It's gotta be high in minerals because it tastes great lol. I bottle it and take it to work. It leaves behind calcium deposits anywhere it evaporates. Plants don't seem to mind though. I thought I saw a lockout from too much calcium once, but it went away with the next res change.

It's a shame you glued up your pipes before deciding to switch. You could have sprayed lengthwise into a separate pipe that tee's into your main stack.

I also don't trust the pump switch. Do you have a pressure relief valve?