WARNING place ACINFINTY sensor at least 6' from 600+ watt ballasts

TL;DR: If your ballast is too close to your ACINFINITY temperature/humidity probe, it can stop working, i.e. your tent will overheat and be soaked. This thing has been a godsend for my grow, and I highly recommend it, but don't keep the probe within five feet of your ballasts.

*added vague "probe not working" to title for Google searchers

I'm in flowering, and my lights come on at one in the morning, so it was extremely lucky that I woke up at two thirty and decided to check the tent. The first thing I always do is peak at my ACINFINITY control module to see the temperature and humidity. This time, those fields simply displayed two dashes "--" and the fan was off. My heart probably stopped for a moment. I unplugged and re-plugged the sensor, and it came back, reading 97F and 68% humidity. I quickly opened the doors (which in hindsight I should have done before messing with the sensor) then looked back at the controller, and the probe signal was lost again. I set it from auto to on, and set out to contact ACINFINITY support. Chatting online (I had to wait until business hours, but the advantage is you're talking to a real employee familiar with the product) they found my problem immediately. Apparently, some (or maybe all) probes go haywire if they're placed "too close" to a high-watt ballast, I'm assuming from electromagnetic fields. I was running a 400w ballast, and a 600w ballast dimmed to 400 w for veg. When I switched to flower, I replaced the 400w with a 1000w dimmed to 600w, and turned the 600w ballast up to 600w. My ballasts were on the floor outside of and up against my tent, ~4 ft from the probe. I moved the ballasts just a couple of feet, and incidentally onto my work bench, and haven't seen the problem since.

Whelp, super-long time lurker here (Thanks for all the knowledge!) and I finally reset my password so that I could post this. Seemed important enough. I'll be posting in the grow room design thread, as well.


Well-Known Member
Mine is within 2 feet of both my 650w drivers without a issue for the last year.