Seedling issue in HPA

rootedrichie

Active Member
I have my HPA system set to mist 3 seconds every 2:30.
When I move my seedlings into the system the growth has halted and no progress for almost 5 days. Seedlings are about 2 weeks old
PH 5.8
Res temp 68
No nutes just ph adjusted
 

fragileassassin

Well-Known Member
what did you start them in?
if you take them out of something else and put them in a hydro system they will stall for about a week. watch the roots
 

Larry3215

Well-Known Member
I would suggest you try a different timing schedule when first putting new babies in the system. Its a good idea to over wtaer at first.

I dont know your flow rates or chamber volume, but cut the OFF times way down. You need to over water them in the beginning until they get used to the new environment. You dont want the roots to dry out.

Im ging to paraphrase Atomizer but need to give him credit. I would suggest you search as many of his old posts as you can find.

HPA is not like LPA. You dont want to soak the roots them have them dry out. You do not want to have too long an ON time or too long an OFF time.

The goal is to create as uniform an environment as possible - without distinct wet/dry cycles. You want to be like Goldilocks and have it just right all the time - not too wet and not too dry. Your ON time should not leave the roots dripping wet, and they should never be allowed to dry out at all.

You want to have an ON time that is just long enough to fill the chamber with a mist of very small droplets - in the 20-80 micron range. That should create a mist that "hangs" in the chamber for at least a minute or longer. Your OFF time should be shorter than the hang time. You want to start the next cycle before the mist is completely gone.

You need to let the roots guide you on setting the times. If your ON time is too long, you will see the roots holding lots of droplets of water. They will also stay smooth - like LPA roots - and head straight for the floor of your chamber. When you get it close, your roots will start to produce fuzzy hairs. Too dry - meaning too short an ON time OR too long an OFF time - and they will air prune.

The roots will tell you what settings to use.

In the beginning though, you need to over water. After the new babies roots start to grow and put out new shoots, you can start to cut down the over all flow rate by lowering the ON time and slooooooowly increasing the off time.
 

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rootedrichie

Active Member
Thank you Larry I have followed him and read most of his posts actually. I just hardly post and need to figure this out. So right now
I’m currently dropping seeds in water for a day then into rapid rooters it took about 4 days till the two root was out the bottom. I carefully removed it from the cube and placed it into the HPA system. But when I am doing this it’s halting everything.
The seedlings are still erect and look fine top side. But I’m not seeing even an inch of growth on the root after 5 days now.
Water phed down to 5.8
Chiller to 68-69.
I did just drop the schedule to on every 30 seconds instead of 2:30

I see some people leaving in the rooter cube and going into the system? Would that be more ideal? And if so should I surround the cube with growstones or clay pellets?
 

Larry3215

Well-Known Member
I agree on the be patient thing, but keep an eye on those roots. The roots will tell you what to do.

I agree about NOT leaving the baby plants in the rapid rooters. They will hold too much water, so I thiink you did good on that. I never use any medium in my systems - just bare roots. I start my seeds similarly to you, but I use mini hempy buckets - just dixie cups filled with perlite with small holes about 1/4 of the way up from the bottom. After one week +- in the cups, they go into the system - basically as soon as there is enough stem for the foam puck to hold on to.

You wont see much if any top side growth until the roots start growing strongly. In my experience, the top side doesnt grow much at all until the roots get well established, and adjusted to the new environment. As mentioned before, that takes a good week or so +-.

I have noticed that the top sides dont start really rapid growth until the roots reach the bottom of the chamber. Im not sure why, but that has been my experience. They should reach the bottom pretty quickly once things take off. I usually see at least one and often two or more different shoots go straight for the bottom while the upper parts decide if they want to grow more sideways. It will depend on your system flow rate and how wet the roots are, mist density etc.

Roots that have large drops held on the very tip are the ones that go to the bottom. Those drops weigh the root down and the root then thinks it has found water and grows that direction - sometimes. Roots can be contrary, and grow UP instead of down or even in circles. If you are over misting early on - which you should be - then your roots will be over wet and have large drops. That should guarantee at least some go straight down.

Depending on the depth of your chamber that can be pretty fast. My root chamber is about 29" deep and it generally takes two to three weeks for the roots to get to the bottom. As you reduce the flow rate, they will begin to spread out and turn fuzzy. Thats when the balancing act begins where you try to find that Goldilocks mist density and flow rate for your system.

I start my seeds out soaking in plane un-PHed tap water. Once they are in the hempy's, I start them on about 200-300 PPM PH'ed to 5.8. My tap is under 100PPM most of the time. I use Jacks 321 hydro with no other additives. Over the next week I slowly increase the PPM to about 300-400 or an EC of 0.8EC. Thats the EC I generally start at in the system. That way they start in the system at the same PH and EC they were at in the hempy's. Thats two less things to adjust to.

After they get into the system, I will adjust EC up/down depending on what the leaves look like. I rarely get over 0.8, but I did have one strain that liked closer to 1.2, so it is strain dependent.

Post some details, pics of your system. Im curios how you have it set up - # and type of nozzles, size of root chamber, # of plants, etc etc. Im always interested to see how others do it. I get some of my best ideas from other people :)
 

rootedrichie

Active Member
I’m actually using flood tables that are about a foot deep. I know I know bigger chamber. Soon each tray is 4x2 with 3 misters per side and 2 on each end. I totally know what you mean by the droplets. Here my issue tho I put 10 seedlings into the tray and practically all of them haven’t even grown an inch of roots.
I put a couple of the seeds in my LPA EZ cloner and they are gaining roots. That’s why I’m so confused. This is my second run in the system last time the plants were already like a month old before going into the HPA.
 

Larry3215

Well-Known Member
Well, on the one hand your system setup isnt quite the ideal HPA model system as far as design. ;)

On the other hand, your babies dont look unhappy at all, so you are not hurting them.

I think this still comes down to just give them some more time.

You might consider giving them a small amount of nutes - no more than 200-300 PPM tops - and see if that helps.
 

rootedrichie

Active Member
I know I know I’ve got an accumulator coming on the next go around. My tap water runs about 100ppm. At this point it only has Impello Tribus and Ph down added to the water.
So I’ll add some and see what happens
 

rootedrichie

Active Member
Just so you know I have a flower room I switched over to the spray when they were about a month old this last run. They are almost finished and imo did great without the whole accumulator setup and what not. I did have the real white hairy roots in the beginning but ran into some heat issues. Anyways here’s what the flower room looks like. To compare

The difference in the veg room . I decided to actually drill holes in the trays and I felt it gave it a more uniform spray than they way it’s setup here obviously
 

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