Cause of hermies other than light leaks?

[frikn squirrel]

I have been getting lots of hermies during the last 4 grow cycles after moving to a new place. Since I'm growing the same strains I usually grow, I suspect the issue is environmental.

Plants look super healthy all the way through flowering, temps and humidity are good. I don't see any bugs aside from a few fungus gnats. My water is tap water that sits for 24 hours, but I think it is high ppm and the ph is 8.5+. I've done runs in organic soil and with botanicare nutes.

I suspected that since all of the above looked good the issue must be a light leak somewhere... right? My partner and I have cleared out all of the plants in the flower chamber and turned the lights off and sat in there for 45 minutes in total darkness looking for light leaks. I would think that with all of the hermies I am getting (at least 50 per cycle... varies by type of strain) the light leak would be pretty obvious but we couldn't see shit.

So what else could it be? There is a water heater in the corner of the room... could that somehow leak light or off gas something? There are also some old metal waterpipes running along the ceiling. Also, a furnace that rarely gets used

I have all of the little LED lights on my timers, surge protectors, etc covered (theres even one on the furnace).

Hot air is exhausted out of the basement with an 800cfm fan, there is a 250cfm fan pulling fresh air in.


So what could it be??????

 

[im me]

stress will make hermies real quick if youe rooms light proof I dont know what else it could be.

 

[PerroVerde]

What is your root zone temperatures like? I had a run flip dicks after the room heater stoped and the room hit 48° at week five. High and low PH can make it happen as well...

 

[GMT]

ph of 8.5+ is not good.

 

[Avinash.miles]

root zone temp def ime has caused hermies where the room was well regulated environment, no lite leaks,
i watered w cold cold water a few times and experienced many herms that were otherwise unexplainable,
cold roots can cause herms def in my exp.

aside from stresses caused by environmental swings like hot nites, or lite leaks......
u r talkin genetics.
they are genetically inclined to herm, cause mama and.... mama got it on at one point in time, or some botanical equivalent of that

 

[AzGrOw-N-sMoKe]

With that severity of herms id be watching for lights coming on during the dark cycle... timers love to act buggy an if you've been messing with em without clearing the old data first increases these bugs... other then that id be checking temps during lights on, a heatspike high enough can cause herms in'a very short time of exposer... Az

 

[frikn squirrel]

Thanks for the responses so far!

Just to be clear, the ph of the water out of the tap is 8.5+. I definitely ph it to 6.5 for my soil grows. The water sits out at room temperature so it isn't extremely cold - probably 65ish.

I am monitoring temps with two different min/max thermometers and the floor, the ceiling and underneath the lights are all within the target range. Certainly nothing extreme...

 

[Tom Hill]

ph of 8.5+ is not good.

Agreed along with whatever is causing such a high pH, that would be my guess as well.
I have not even been able to get seed to germinate under those conditions approaching pH9, seeds just turn to mush. Definitely a problem.-T

 

[PrimeTimeNugs]

are you going from seed or clone? and 8.5 is for sure no good, are there red leds on at night, from pumps and solenoids? thats no good.

 

[Kcar]

Stress is causing your plants to hermi. Find the source and eliminate it.
Sounds like your water. Good Luck!

 

[Shulman]

most often its major stress from photoperoid so if its not that it can only really be growing medium,nutes or water or seeds that are prone to hermie.

 

[Bruja64]

Agree with Tom Hill.
One time I had the same thing happen. Couldn't figure it out until I realized the ph was off.
My solutions was to slowly add dolomite lime, now, that cleared it up for me. Some would use Cal-mag.
Might try it out on a couple of plants. When I did it, I tried it on several that had been in veg for about 4 weeks(I know yours are in flower), and these babies all turned out fine.
Sometimes we just try so hard to get everything right, we forget the "little" things that we learned in the beginning!
Anyway, hopefully it is a ph thing and clears up easily for you.

 

[eric2028]

some strains cant handle a light prune in flowering. also check for light leaks at different times of the day, on sunny days especially. here in MI its gray so much u cant really spot a leak at times! also ive found cheap ducting is transparent so u might have to wrap some panda paper or something where its entering or exiting. good luck!

 

[OrganicBuds]

Things that I have over looked that have caused hermi's:

Keep the soil moist, too dry and it will cause hermi's
Check all timers, we are pot heads and maybe we set one of the lights wrong.
Don't prune in flower. All the old grow books teach you to trim up your plants during the first two weeks of flower. With how sensitive strains are these days you can't trim at all during flower, without taking a risk.
High to low temp swings

 

[SeaMaiden]

It was when some rock solid genetics hermied that I finally considered root aphids. And there they were, in all their glory. Very stressful, very stressed plants. So, that's another thing that can cause hermies in plants that have otherwise been working great before.

 

[Jhhnn]

Agreed along with whatever is causing such a high pH, that would be my guess as well.
I have not even been able to get seed to germinate under those conditions approaching pH9, seeds just turn to mush. Definitely a problem.-T

Seems likely it's the water, particularly if the other aspects of the basic growing routine are unchanged. RO might be the answer.

Dunno if the water heater is gas or electric. If it's gas, I'd check for light output when the burner is on, and I'd make sure I hadn't picked up root aphids or any other weirdness.