Grow Mediums Rez on from germ?

[Carphunter]

I'm curious if any one has ever had their rez on from germ to end, instead of top watering and turning the rez on later? I'm currently finishing up my first autopot grow and loving it. During this grow an idea has been brewing in my head. When using an autopot system the media (straight coco/perlite in my case) only uses water in two ways, evaporation and plant uptake. Once the rez is on these two factors are handled, maintaining a near constant environment withing the media. I can understand top feeding if transplanting into the system, needing to get the roots to begin spreading out. But not if germinating directly in the system.

Here's my idea. Germinate directly in the system with the rez filled and on, media precharged with same mix as in rez. Start increasing nutrient content in rez, at the the same rate as you would if top watering, you just never have to top feed. This should allow plant growth and specifically a root system that is optimized for the consistent environment within an autopot. This would bypass any chance of stress or stunting due to transplanting. While also mitigating any chances of either over or underwatering during the formative first few weeks of the autoflower growth cycle.

What say ye?

 

[jdsworld]

problem is when small they only require a lil bit of water and the aquapots keeps them too wet for first 2 weeks. At least that is my understanding of why you don't turn it on right away.

 

[St. Tom]

a tiny seedling as far as im aware needs more oxygen at the roots i also use autopots and the top feeding isn't an issue for me but if you want to try it id be interested on how you get on

 

[Olderfart]

I too would be interested in how this works.

The two issues that come to mind are early overwatering, which is already covered, and root development. Starting in small pot may result in better root penetration throughout the final medium. Starting on the rez might cause most root development in the bottom of the pot. OTOH, this may not be a problem even if it happens.
An additional possibility is that longer time on the Rez could bring on salt buildup earlier.
l’ll be watching with interest.

 

[Carphunter]

I really don't think overwatering would be an issue. Whether using plastic or fabric pots in an autopot system the moisture level is not consistent from top to bottom. The top is always dryer than the bottom, with gradation along the way. It is however consistent is how much variation in moisture occurs. The reason you can't underwater in an autopot is the same reason you can't overwater. It's the consistency.

I think the most natural analog to a autopot system is that of a desert oasis. Notice that plant life thrives even tho it never rains. The way an oasis works is by bottom irrigation. There's a consistent water supply bellow ground, creating a gradation in moisture levels as you move upwards from water supply to surface. Just like a autopot.

If the plant doesn't want a lot of water, it's root system will grow sideways, branching out. Because that is the direction of a consistent layer of moisture. If the plant wants more water, it will grow down, towards a layer of higher moisture. And so on and so forth. Gradually working its way down.

Notice that all the literature talks about transplanting in the context of needing to top water. I believe we carry on with that practice even when not transplanting simply because that's all we know. Not necessarily because it's the best thing.

 

[Nosias]

I use the 2.2 gallon AutoPots with 100% coco. The coco is always wet.

 

[Carphunter]

Yes the coco is always wet, but not evenly. The amount of held moisture in the coco lowers as you go up from the tray. Basically the surface is dryer than the bottom at all times, even tho its still wet. This is easily visible if you grow in the fabric xl pots like I do. You can see and feel a gradual change from dryer to wetter in the cloth itself. Closest to the tray if you wipe your finger across the pot it will come away wet, whereas at the top the fabric is dry.

I'm going to test out my theory on my next grow. Just waiting for the new tent to come in. It will be a clone of my current setup.

I use the XL fabric pot version, and run them inline instead of tee'd. I'll add another shutoff valve between the two pots, so one will be on rez from the start, the other I'll top water with the same water from the rez. See what happens.

Should be a good test. Both plants in the same tent, with same environment, being feed the same solution. Only variable is having the rez on from the start for one and not the other.