My 4 year old wanted to grow something in our garage garden so since we cook a lot of Asian food (my wife is Filipino), we decided we should plant some Bok Choy.
Now, keep in mind that Bok Choy is NOT a warm weather plant and our garage easily gets close to 100 degrees so I wasn't sure if this would even work, but I figured it's worth a try.
4 Year Old Chloe Planting Hydroponic Bok Choy
90+ Degree Rez Temps
So throughout this grow, the temp was between about 75-93 degrees (water temperature). That is in and of itself pretty amazing for any plant, let alone a plant which tends to go to seed once it gets above 70.
On top of that, I did NO water changes for the entire 30 days and only adjusted pH 2 times. This wasn't intentional, but I put way too much nutrients in at first like an idiot and about killed them, so I just kept diluting the water as it evaporated. I added new water 3 times during the grow (RO water only, no nutes).
At 90+ degrees, the water can evaporate relatively quickly, in fact there is some yellowing of the tips of some of the leaves here because I left it while on vacation and came back to maybe 25% of the water left in the rez which meant my PPM was insane (1.5k!).
But, all in all, I think they did pretty well given the circumstances, even with all that heat and lack of water changes and drought, the roots were pearly white!
After 2 Weeks
After 30 Days
So What's The Secret To Mitigating Against High Rez Temps?
I honestly don't know. I have never grown anything in an environment as hot as this before and I tried a few new things at once so it's hard to tell which one made the most difference.
There are 3 things I believe to have affected the plant's resistance to heat:
- Silica: I used GH Armor Silica Shield on this grow, which claims to make the plant more resilient in general and helps it protect against heat in particular.
- C02 Supplementation: I am using an Exhale Homegrown C02 bag in this tent. This adds between 800-1000 ppm of C02 depending on how tightly I seal up the tent. It is known that with these levels of C02 plants grow better in (and even need) higher temps.
- Venturi Pump: The DWC I am using for this grow is the Fizzy Farm Indoor, which uses a Venturi pump. A Venturi pump increases the ability for the plants to handle warmer conditions. It has been shown before that growing at even 100+ degree temps is possible with a Venturi pump, so that may have had some effect on this grow as well, however for the first week or so it was run on air stones only as I accidentally got the pump clogged with coco and it took me a while to separate it from the water.