Hitting 2.4 a light, but having to adjust pH with Hugos.

[ClownKiller]

The last line on the Water pdf might be helpful.
"Right after the last cycle of the day, use a syringe to extract a water sample from the block. Test the sample and if the ph or ec is too high add an extra water cycle the next day."

If the block is too heavy for another water cycle I'd guess to give less volume per cycle. Or maybe try less cycles and see if the ph goes up even more as a test.
The syringe idea sounds easier than the three handed pour thru, gonna have to try it with the turkey baster

 

[This_is_me]

The last line on the Water pdf might be helpful.
"Right after the last cycle of the day, use a syringe to extract a water sample from the block. Test the sample and if the ph or ec is too high add an extra water cycle the next day."

If the block is too heavy for another water cycle I'd guess to give less volume per cycle. Or maybe try less cycles and see if the ph goes up even more as a test.
The syringe idea sounds easier than the three handed pour thru, gonna have to try it with the turkey baster

The syringe is the best way to get the water sample, the only issue for me was that every time I have to poke a hole in the cube and Grodan folks talk a lot about its integrity.

I simply took a 5 gallon bucket, a 9" Hydrofarm square basket (it fits perfectly over the bucket), put the test cube inside the basket (to eliminate the need to touch it and squish it), and poured 1 liter of pH-ed water over the cube. I measured the pH of the resulting run-off. First time, second time. etc.

 

[HarvestMoon303]

At 2.4 per light, I wouldn't give a fuuuuuck...

I came here to say this too. Nice looking plants, I would just keep it up.

 

[High Grade Only]

So as i explained originally, i have tried soaking cubes at a lower pH (3.5 all the way to 5) with no luck solving my fluctuations. And I only veg for 4 weeks. These for instance were transplanted 2 weeks from being cut into Hugo, the Hugo were fully saturated at 5.5 , then stacked to drain. They were fed super light, around 3 oz per day increasing over 4 weeks to 40 oz, at a pH of 5.2. .