Grow Mediums Using an Autopot aquavalve for a tray of small containers of coco (SOG)?

[parsing_trees]

Do any of you have experience with using an autopot aquavalve to bottom-feed a tray of smaller containers? I want to set up automated watering, and using an aquavalve seems like a good fit because I've been bottom-feeding small containers for several grows, just watering by hand. I like that growing style a lot, but some automation would allow more time away from the grow. I tried searching this subforum, but aside from this thread, the posts I've found about small containers generally assumed transplanting.

I have a deep bottom-feeding tray for my tent (2x2' / 60x0 cm), an easy2go kit (aquavalve and tubing), and an in-line tap / shutoff valve. I have ~14 gallon / ~50 liter plastic bin I've used as a reservoir before, when I was using a timer, pump, and drip lines.

Their setup guide says "minimum pot size 1.3 gallon", but is that assuming soil? I would be using coco/perlite, and when bottom-feeding I typically use four 1-liter air-pots or six 1/2-liter solo cups or other plastic containers. Would the smaller, and particularly shallower, containers be a problem? I typically put a layer of hydroton/LECA at the bottom of solo cups to add an air gap for drainage and root space, like what the air-pots have underneath the base disc. Would using a mix of container sizes be risky, because it might keep the larger containers well watered but could over-water the smallest ones and risk cause mold? The aquavalve doesn't allow any control for how long it delays refilling the tray after it runs dry; I'm hoping it'd at least be fine to use watering for up to a week while traveling, but if I could use it the whole grow after the first few weeks (when I normally switch to bottom-feeding), that'd be ideal.

I'd be using the same hydroponic nutrients (Dyna-Gro) I've used for other bottom-feeding and irrigation, no change there. They seem to stay pretty stable in the res for weeks at a time.

I've seen several references to pot socks -- those are to keep roots spreading out into the tray from growing into the aquavalve and preventing its double float valve from getting a proper seal, right? I typically get some root growth into the tray when bottom-feeding, but eventually they air prune. I would probably only be leaving the grow unattended for a week at most, so I would be able to keep an eye on roots or coco, perlite, etc. in the tray. Perlite in particular does tend to get around.

They advise against putting an airstone in the res, just a pump to keep it circulating occasionally at most. I would probably set up a small aquarium pump with a venturi aerator on a timer, running 15 minutes a couple times a day. I'd keep the res elevated for gravity flow, top up once a week or so, and shut off flow for full cleaning as necessary.

I normally top-water once every week or two to wash out any salt buildup. Should I do that with the autopot kit, and should I turn off the valve for the day when I do?

Any other general comments about using an aquavalve to water a tray like this? Thanks all.

 

[420autoflower]

Have you ever considered ebb&flow? I would think it would be much easier to set up and manage compared to using an auto pot system for growing SOG.

 

[parsing_trees]

Have you ever considered ebb&flow? I would think it would be much easier to set up and manage compared to using an auto pot system for growing SOG.

Sort of, but managing the height of plants in my tent (5'5") to not grow too close to my lights has been an ongoing struggle, and growing on top of an ebb & flow reservoir would eat further into that headroom. I can't get a taller tent because of the ceiling where I keep mine. I've only read very basic info about ebb & flow, though, so maybe there is a way to set it up that wouldn't? I've been looking at autopots because what they automate is very similar to how I water otherwise.

Also, I wouldn't be opposed to growing in mostly hydroton/LECA rather than coco. I'm most familiar with coco though, whether with drippers, bottom-feeding, or hempy buckets, and water retention in the coco gives a safety margin if watering fails.

 

[parsing_trees]

I looked some at @Animatey's ebb and flow grow a while ago, which is (IIRC) in a similarly sized tent, but that's just one plant. I like doing a hodgepodge of different strains, otherwise I'd probably do one plant in a big hempy bucket. While not essential, some tolerance for power outages is also nice.

I know that's a lot of requirements! Not trying to be difficult.

 

[420autoflower]

Sort of, but managing the height of plants in my tent (5'5") to not grow too close to my lights has been an ongoing struggle, and growing on top of an ebb & flow reservoir would eat further into that headroom. I can't get a taller tent because of the ceiling where I keep mine. I've only read very basic info about ebb & flow, though, so maybe there is a way to set it up that wouldn't? I've been looking at autopots because what they automate is very similar to how I water otherwise.

Also, I wouldn't be opposed to growing in mostly hydroton/LECA rather than coco. I'm most familiar with coco though, whether with drippers, bottom-feeding, or hempy buckets, and water retention in the coco gives a safety margin if watering fails.

I agree! Having my plants sitting on a reservoir has always been a challenge. I’ve been lucky and haven’t had a big problem yet but very close. I do whatever I can to keep my canopies maintained at at a lower height but sometimes it becomes difficult and end up super cropping or use training clips and sometimes scrog netting.

 

[parsing_trees]

I agree! Having my plants sitting on a reservoir has always been a challenge. I’ve been lucky and haven’t had a big problem yet but very close. I do whatever I can to keep my canopies maintained at at a lower height but sometimes it becomes difficult and end up super cropping or use training clips and sometimes scrog netting.

I think if I was running a larger tent or room, with space for a table, ebb & flow would clearly pull ahead. It seems harder to scale down though, especially since I like to grow strains like Hubbabubba Haze or Mango Smile that love to stretch. I'm doing small containers in part to help manage height.

 

[420autoflower]

I think if I was running a larger tent or room, with space for a table, ebb & flow would clearly pull ahead. It seems harder to scale down though, especially since I like to grow strains like Hubbabubba Haze or Mango Smile that love to stretch. I'm doing small containers in part to help manage height.

Here is one I harvested a few months ago that got a little out of control on me… had to do extreme measures to maintain the canopy. Lol! I raised the lights as high as they could go and super cropped and clipped the hell out of the branches to keep everything low enough.

 

[Olderfart]

I expect that the setup you plan should work fine, although I have not done exactly that in any of my autopot grows.

As to your specific concerns:

Pot height - I doubt that volume will make any difference, but pot height might. Lower pots will be wetter. I have not used pots as small as you are considering, so I can't advise with certainty how they will react. However, in my coco/perlite/autopot grow in 3 gallon fabric pots, I had healthy roots concentrated throughout the flood zone, so I see no reason why shorter pots should be risky with coco/perlite with a normal flood sequence. Note the word "normal", more about that later. I'm not sure what Autopot is on about regarding the minimum pot size, but I don't see why pot volume should affect function unless they are talking about smaller pots not properly filling the trays.

Hydroton under pots: - I would not do it, just make sure that your plastic pots, if that is what you use, have holes all around the lower edges. Water will get to all sides of your small pots, and that will fertigate them perfectly. Putting hydroton beneath the pots would signficantly alter flood sequence, likely by lengthening it because wicking up into the pots would be reduced, and roots would have to colonize the hydroton to use the liquid there and trigger the flood sequence. I would not put it inside the pots either unless it is mixed throughout as @pop22 does. You need the finer material in the bottom of the pot to facilitate upward wicking.

Another related issue for the flood sequence is that the tray setup you plan will have more water outside the pots than inside them when the flood sequence fills to full height. This could lengthen the flood sequence so much that the flood zone is not aerated enough between floods, leaving the medium too wet. In my multi-10 gallon setup I dealt with this by anchoring closed cell foam inserts between the pots to ensure that no extra water needed to be absorbed. I don't know how my setup, or yours, will work if the volume of water outside the pots is not reduced because I have not tried it.

Pot socks - I just pruned roots in my setup, and that kept mischief at bay. You will need to watch this, and could reduce risk by installing a barrier of pot sock or other material that increases the length that roots have to extend to get to the valve. If you keep them pruned and make sure they are cleaned up before you leave, you should be ok for a week, but monitor before you leave to get a sense of how quickly roots are moving.

The perlite is in my opinion a bigger issue than the roots. You need to keep that stuff out of the valve area. If you are using plastic pots with holes, you should consider putting filter material on the pots to prevent perlite from escaping, and/or some kind of filter setup around the valve to prevent stuff from reaching the valve. Panty hose material might do nicely. If you put filter material on the valve, it cannot be loose enough beneath the valve to allow it to float or bunch up beneath the inner float. If you put anything beneath the valve, it needs to be stretched flat. You might guess how I know that. In my grows, I also installed a pleated household filter inside the reservoir to make sure that nothing could get into the valve from that direction. If anything gets jammed in the internal valve while you are away, you will have a flood.

Stirring the reservoir - I just stirred my reservoir manually when I was around to do it, and never had a problem that I recognized. Jack's Nutrients recommends and air stone in the reservoir to oxygenate the nute mix, and I will try that in my next grow. If your reservoir has not been a problem with your nute package before, it will likely be fine without stirring or aerating, but I doubt that adding one of these would do harm, and maybe Jack's is right, and it would help.

Nutes - If your nute package has worked well in sub-irrigation for you before, it should work fine with autopots. Your suggestion of top watering periodically to flush the coco is good. When I do it, I turn off the reservoir, remove the pot and place it where it can drain, do the flush, and then put the pot back in the tray and turn it on. With your setup, I would definitely remove the pots from the tray for the flush, you don't want the salty runoff to stay in the tray or get into the other plants.


If you have not already done so, you might have a look at my sticky on troubleshooting the valve here: Troubleshooting the Autovalve | The Autoflower Network There may be information there that comes in handy.

Good luck with it, please tag me if you do a journal, I would love to see how this works for you. I have considered setting that sort of system up, but never got around to it.

 

[parsing_trees]

Thanks for your detailed reply!

About hydroton under pots: Okay. The 1L airpots have a small air gap under them, but I have usually added a wick to give the roots a head start until they grow past the air gap and down to the tray. With the solo cups, I don't start bottom-feeding until the roots have spread to the hydroton layer, which is probably small enough that the autopot's fill layer should still contact the coco. I've added that because I noticed that the roots in airpots really liked that small air gap, and all my solo cup plants responded very well to adding a ~1/2" layer of hydroton. Before that I had roots plugging all the holes I've drilled in the cups and causing drainage problems, then root rot.

Putting something inert between the pots to take up volume in the tray is an excellent idea, and would allow some control over how much it floods, which could be fine-tuned over the grow.

Stirring the reservoir: I previously used an airstone in my reservoir, continually bubbling and buzzing. (The venturi aerator should be much quieter.) A little aeration on a timer would probably be plenty. I haven't had problems with nutrients coming out of solution, but I will have a filter on the autopot intake just in case.

I will check out the Troubleshooting the Autovalve thread, and if I decide to go this route for my next batch (likely around late December/January) I'll tag you.

 

[Frogger]

. I don't know how my setup, or yours, will work if the volume of water outside the pots is not reduced because I have not tried it.

I tied it last spring with 3 cloth pots in a modded ( 4 the valve) 12x18 tray. The excess water made the pots tooo wet . Never thought about the closed cell trick