Easing into hydro, could use your knowledge! Autopots and QB's

Hi everyone I’m planning on starting my first hydro grow in a couple weeks and would love to hear your thoughts if anyone feels like chiming in! I’ll try and list my set up as simply as possible. The strain I will be growing is ILGM grandaddy purp.

2x4x5 tent
3x 4 gallon autopots with 12 gal reservoir
260 watt xl hlg qb
3-part general hydroponic nutrients (flora, bloom, micro)
pH pen + TDS meter
50% coco 50% perlite media
6’’ inline fan with filter and a few clip on fans for circulation

I have a few other odds and ends but thats the core of my setup. I plan on vegging at 18/6 until the net is as full as I want it and then switching to 12/12.

I have a few questions on some of the stuff that is very new to me.

  1. What else do i need for nutrients and supplements? I’m used to growing in soil without the need for much in the way of nutes so trying to plan what my plants will need ahead of time in a 12 gallon reservoir will be a new challenge for me.

  2. I’ve never used the qb for veg and was wondering what distances/dim settings should I have in veg / seedling stages? If the qb is too much for seedlings i do have a 240 watt blurple I could get dig out if necessary.

  3. I should also add that the water i use is from a well. From the tap it has a pH of about 7.7 and a ppm of ~80-100. With the hydro setup will I run into problems with a ppm that high? I plan on pH adusting everything to as close to 5.8 as possible after adding nutes.

I’m sure that there’s a bunch more that I’m missing but thanks for reading and I’m happy to hear any suggestions!


@Screwauger @Blasting


I’m about to start my 6th autopot grow. I have the 2 pot system witrh 4 gallon pots and 2 12 gallon reservoirs.

Welcome to the forum if your new, nice to meet you if you’ve around a while.

I love my autopots but they do come with some inherent set backs. One being the careful hand watering of new seedlings and sprouts, the other being clogs or flow issues.

Additionally, I grew in coco/perlite initially but I had a great deal of cal mag issues and some other growers recommended promix. Didn’t help as I still had what looked like cal mag issues. I grow mainly auto’s.

That said, I believed and still believe that my cal mag issues related to the tray ph as opposed to the res ph. The aeration and stagnation in the tray almost always leads to a higher than desired ph causing lockout (my theory only). I am just cautioning you and I will add, my first grow was with the nutes you have selected and did not have as many cal mag problems. I also used the modified lucas formula with the GH nutes eliminating the grow bottle completely. I had over 13 ounces from two scrogged plants.

The one thing I am very confident in stating, your space is much two small for three 4 gallon autopots. I know because I have a 4x4x7 foot tent and a two plants scrog was too much.

I just harvested a purp haze auto from my autopot, grown alone and the total was nearly 12 ounces (11.5+/-). Autopots, when dialed in, grow larger plants similar to good hydro set ups. Just my input. I bought a third pot and tray and use them as back up as two plants are max (I realize in a scrog, you may get away with 3 but it will be sure crowded.

As for nutes, you seem to have it covered. First ever grow or getting swinging again or tons of experience?? Final four weeks of flower you might uses some kool bloom or other p-k boost and really any supplements as long as they are not organic based. Oganic nutes will settle out and clog autopot lines nearly every time.

Others will have input too I am sure. There are starting to be a few autopot growers here!!! I love em, likely never grow any other way. @TwoLidTony (love the username hahaha)


Thank you very much for the reply. It’s funny I had a friend telling me about autopots quite a while ago and was on the verge of buying some when I saw a thread of yours and that was the determining factor in my purchase. I’m new to the forum and couldn’t remember your name or the name of the thread so I’m very grateful for @blackthumbbetty tagging you.

Thats very interesting to hear about the pH differences between the res and the trays. I wonder if in the beginning when the plants aren’t consuming much solution if i should keep the res level around 50% so it has less time to climb in pH before trickling into trays.

I should probably stick with 2 pots for the first go around. The only reason I was thinking of three is because I planned on germing 3 seeds in hopes of getting 2 to sprout, but if three pop then I was planning on using all three.

And I’m very new to growing. I inherited a couple of autos from a friend who moved a while back and yielded a whopping 3 grams dried weight from them and have been very interested in progressing from there. I’m at the tail end of my first grow in a tent and soil and had a blast. I’m nearing the end of flower and am very much looking forward to some small seedlings that need attention and bendy veg plants begging to be LST’d.

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Yes, that’s what I do also. In fact unless planning to be away I usually mix 5 gallons and pour in (for one plant) and that will last about 6-7 days unless peak growth.

I did this two grows back and had one plant in a bucket with airstones as I had not purchased a third set up. I ended up taking two of them outside as it was just too crowded. Here is a pick of one autopot plant in a 4x4 just to put a visual on there. Thats an auto too, not a photo (spelled grow bigger hahaha).

I’m helping at least two autopot growers currently who over saturated their coco (plants) by over loving them in the first few weeks and/or starting the auotpot rez too early. Not sure what all your plans are (sow in pot, transplant into pot, etc) but untill the plants largest leaves are as wide as your pot, easy goes the liquid and no rez.


Alright you’ve convinced me. I’ll go with two plants in the tent and scrog them. If its still too crowded i won’t be able to say that you didn’t warn me haha.That is a powerful auto, I’m thoroughly impressed! Did you do any topping early on? or is that just LST?

After i get my media pH adjusted and have some sprouted seeds I’m planning on moving them directly into the 4 gal pots. I was planning on doing so when the media is moist and not saturated and leaving a clear cup over them for a little while with occasional misting until they’re established. I’ll try to hold off on the res as long as I can. I like the idea of starting it up onces the leaves have breached the sides. Thats a simple rule for a simple guy like me to follow!


I have a fairly rigid method developing for my auto’s. I remove only leaves that die and I do only gentle LST by pulling branches out and down and anchoring opening up the center of the plant to more light penetration. Some top autos and mainline and do all sorts of things, not I. I do nothing to slow their growth in the first 5-7 weeks; which is why I don’t transplant autos (fems different story).

This is not my “rule” this is general instructions from autopots. Kind of shocked me one other grower did not know this. Autopot literature drills the point home that for the first 21 days approximately (or until the largest leaves on the plant are approx as wide as the sides of the pot) the reservoir will not help but hurt the plants. There needs to be a tap root and root structure descended far enough down in the pot that it is able to wick and use the nutes when the res goes on. Otherwise, nothing but troubles.

Don’t intend that as a scolding hahaha but seriously it’s not a choice or if you can hold out that long, it is the recommendation of the manufacturer and I am here to tell you, I know folks right this minute that may lose their plants because they turned on the res when they thought they should but, was about a week too soon.

Your results may vary but frankly, Ive read about 40 autopot grow journals and this is not an optional recommendation.


From the brochure:

Allowing your plants to establish once they have been potted up, watered
through and placed in the tray is very important before you turn your system
on. The amount of time it takes depends on many factors, plant type,
temperature, humidity, size of plant. This is generally 5-21 days dependant
on pot size but if you are unsure simply feel the weight of the pot, if heavy
there is plenty of moisture in the pot, if light simply turn the system on


Here’s my start off procedure

24-48 hours before I plan to sow germed seed into pot, I pre charge the pot with several gallons of water ph’d to 5.8-6.2 with a dose of cal/mag equal to half the manufacturers rec amount. Soak the pot well and let drain for 24-48hrs.

Sow germed seed and do nothing until it sprouts. Start counting the day two leaves are visible.

Day 5 give each pot about 500-750 ml of water with proper ph and 1/4 strength nutes.
Day 10 give each pot about 1 liter of nutes mixed to half strength
Day 15 give 1 liter of nutes mixed to full strength (** full strength in autopots is about half the amount on the bottle)
Day 20 1 - 1.5 liters of “full strength” nutes.
onward until the res goes on.


I remember reading in the pamphlet that came with the setup to not start the res right away, but hadn’t fully absorbed the part about letting the leaves get to the edges of the pot. For me that makes a lot of sense and I appreciate it a lot! I’m here to learn from those who have come before me and I’m always happy to read up as much as I can.

And you answered my next question with your schedule! I was going to ask about adding nutrients in the early stages before the res comes on but you beat me to it haha. I’m super grateful to get all of this information from someone who has experience with the autopots.


I did the same. I modeled my first grows after successful autopot guru’s.

The point with initial “watering” is it’s not because the plant needs water. That pre charge of 4 gallons of medium will carry that seedling a long way. The initial watering is to introduce nutrients via water so it’s key to direct those first waterings around the base of the seedling, ignoring the bulk of the outer areas of the pot. We want the roots searching for moisture and finding all that moistness in outer areas still there form pre charging the pot.

You’re very welcome.

I push my plants. Never had a harvest without burnt tips (and more). That said, the continual feeding of the res eaquates to the need to ignore most nutrient bottle amounts and just consider half of that as full strength. In general, anytime I reached 1200 -1400ppm I cooked my plants as evidenced by their reactions. Easy does it, and you can still pull huge numbers.


~furiously scribbling down notes~


You Too ???


Class definitely in session had to bookmark the start off procedure! Set to watching! Good luck on your grow!


@puffer1958 good info on your auto pot.

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Couldnt read everything at work atm, but I cant agree more with @screwauger , do not run 3 plants in that small space! Keep them low height in before flip because they tend to grow crazy once you flip them and then you might run into space.problems like too close to light etc (been there done that). @screwauger is a better teacher then I am and also better at explaining his tought (excuse the french in me) but im here anytime ya need help!


That is great info. Perfect. It looks like you left no step out and that’s almost as important as what someone does write. I really appreciate this info. Just perfect.


MWN, thanks very much for this heads up.Big time.


That sounds like a pretty good theory to me. How do you mitigate this , by lowering the pH at the rez so when it rises in the tray it’s meets your target pH?


Turning into a great how-to autopot thread! Wonderful!

Thank you! And thank you @TwoLidTony for asking the right questions, too.


Now, as far as your qb light goes, I recommend starting it at about 100 watts & 30-36" inches above the tops. Slowly lower it down to 18-24" and boost its wattage as they grow. That’s just me. I’m scared of light burn.