Trichy Bastard
Well-Known Member
I believe there are 3 main issues involved with high temps:
1) Dissolved oxygen to the roots (D.O.)
2) Keeping bacteria/fungus/disease at bay
3) Maximum temps a plant can physically handle
Atomizer posted the results of a higher temp test in post #'s 138 & 144 in this thread. It seems if you can keep the pod insulated and mist with cooler nutes, the pod temps can stay within reason. I assume there is likely not much difference with any other type of setup in terms of plant tolerance. In dwc setups minding oxygen levels gets tougher with higher temps, in proper hpa that's at least not an issue because of all the air. I'm sure anywhere there is moisture, there is possibility of bacteria- especially in the higher temp ranges. Since hpa is probably most easily done without organics, adding some chlorine or h202 is easy enough. In your rdwc you must have a chiller? It's an easy fix for recirculating systems as long as you don't mind the added cost and energy consumption but you have to get a little more fancy with mist chambers I guess. As mentioned a few times before, I will assume that evaporation of the mist helps pull down temps on it's own as well. I was curious about any maximal thresholds for pod temps myself, but have been satisfied there's nothing overly delicate about it. What kind of temps are you talking about?
Also, in terms of water consumption, my understanding is that the mist timings will always be in need of fine tuning due to temps, plant stage, etc. If you pay special attention during heat waves I don't see any reason to worry about that too much. If anything, overmisting seems to be the constant battle, and if increased transpiration occurs, a simply adjustment should sort that out. I hope anyone will point it out if any of these thoughts are incorrect.
I can't tell you how helpful it is to have other aero enthusiasts out there to talk to. It seems to be a very small niche at the moment and most people simply prefer tried and true growing methods (simple or not) with which they are comfortable. But for those of us that like to experiment, innovate and tinker, HPA exerts a pull and allure that is inescapable. I must now admit that I've only read the first two pages of this thread, and I myself can't stand it when people jump in on the last page and ask about things that have already been discussed so I shan't be doing any of that until I completely catch up. But the first two pages were riveting. I had actually begun reading (and am at various stages of progress on) all of the threads you had pointed to e.g. "plug and play pods" and such. I hate to say it, but they will probably take a back seat to your thread here because you have done such a magnificent job of consolidating and summarizing all of that disparate knowledge so concisely and succinctly! I will be building my own HPA system right alongside you as per the information you have lain out. I forewarn you, and those here, that I may end up asking some very noobish questions, even after having read all of your wonderful info. There some aspects of HPA that I have never encountered ever before...things like solenoid valves: so mysterious and magical! I've never seen or handled a solenoid valve before, though I have a basic knowledge about the premise on which they function (thank you internet). It's like an exotic wild animal to me. There is so much that this hobby can teach you that you never imagined 
I like you're attitude and to be honest I didn't have too much more beginning knowledge than you. It's amazing what taking the time to read some good threads will do for your understanding of this. I bet you've worked with a solenoid before- ever played with automatic sprinklers? The valve that turns them on from the timer is the same thing. A dishwasher, or clothes washing machine also utilize solenoids- all they are is electronically activated water valves- simple enough. The accumulator tank is the same as used on people's home reverse osmosis systems, and the rest is pretty simple and straightforward after reading about them. Cavadge was especially good at describing what he was learning to the readers of his thread, so we could learn along with him. In the end, I think he fell slightly short of perfected aero, but he sure taught the concepts well as he went, and I am sure by the end of his thread he was quite capable of doing it exactly right the second time. Anyway, glad to have you onboard, do lots of reading and I'm sure we'll try to accomodate filling in the gaps you need like others have done for me. I highly recommend reading all these threads from start to end before you decide to buy any parts. You'll know for sure if it's a road you want to follow, and you'll have alot better chances only having to buy the right stuff the first time around...
hehe... Yes, I consider silica really good for strengthening stems and helping the plant retain water. I figure it's quite pervasive in natural soil, and feel the need to add it to my hydro despite it being non-essential. Beleive it or not, there are some studies that show the plant uses it to make certain hairs that can possibly be carcinogenic to us. In the case of wheat, which uses silica to grow these hairs, the studies show the middle eastern areas that eat alot of bread incidentally have the highest rate of throat cancer in the world. I figure I'll take my chances though since silica is in all soils (It's basically sand)...