Plants eating less and low ph runoff in flower

I have 5 coco hydro plants on day 23 of flower. 3 jungle cakes, 1 madmartigan, 1 apples & bananas.

Temp 84f, Humidity 40% at canopy. Water every 3 hours during lights on and once every 6 hours lights off.

The roots are compacted in 3 gallon fabric pots. When I water them they puddle up & take about a minute to come out as runoff. Ever since the roots became really compacted my plants can barely take any ppm. Jungle cakes have gone from 700ppm in veg to now 250-300ppm in flower. Martigan & AB was taking 600 in veg & I'm still trying to figure out how much they want in flower. I flushed them down to 300ppm then fed them 250ppm and the runoff is still going up lmao so I guess they want 200ppm per feeding? Never heard of anything like this in flower. Also the pH runoff is 5.5 & input is 6.1

I've been flushing the Martigan and AB with 0ppm water and consistently get 250-300ppm runoff. I think I'm just going to florakleen the fuck out of these plants until they hit 0ppm and start over this shit is wild.

I have a similar problem, but I grow in potting mix and sand. Several weeks after switch to bloom, last irrigation with nutes, the PPMs of runoff salts soared, meaning I need to decrease nutrient PPMs. I chased the nutrients with a few extra flushes of RO water and stopped when runoff PPM had decreased to 1300! The plants never got fed more than 700 PPMs and prior a typical runoff rise had been 150 PPM. Next irrigation I will likely start with RO water, and once salts are down to a reasonable range of a few hundred PPM (if possible), then I'll chase the flush with nutrients until those measurably raise runoff PPMs.

The plants also stopped drying out their pots as quickly and are a day past scheduled irrigation. Potting mix is still quite damp on top, I want it to dry more, they won't get irrigated for at least another day or more. Coco watering strategy is said to be different.

However, my runoff pH is close to where I want it, at about 7. It's because I changed bloom formula N to be all nitrates, I deleted ammonium as N sources and increased nitrates to equivalent N, to get the most alkaline reaction I could. If I was still giving the vegetative formula, it's basically a 50/50 mix of nitrates and ammonium, the runoff pH would be around 6.3 or thereabouts. I've got the vegetative formula dialed in, but still need to work on the bloom formula.

I presume the excess salts in runoff and the decrease in transpiration means the plant is shutting down for some reason, one I don't understand, but one that we both seem to be able to measure.

try yucca extract. sounds like both your mediums are hydrophobic

Are compacted roots a sign of hydrophobic medium? I was doing 50mg per gallon of yucca I'll start adding again but I don't see any solution to this issue. The plant with the most compacted roots is yellowing but the buds seem to be forming fine. The other plants look fine but are not 100% they def have excesses and deficiencies. Two plants have clawing and slightly bluish leaves so I guess too much nitrogen and not enough phosphorus.

I flushed them down to 100ppm but the ph is still coming out at 5-5.4 and I'm putting in 6.2

I'm only running my exhaust fan with no intake fan. Can reduced air circulation cause compacted roots or the issue that I'm dealing with?

A pic of the compact roots might help. My roots got more compact when I switched from sulfate-based dry micros to chelated liquid micros.

zebracake said:

... ph is still coming out at 5-5.4 and I'm putting in 6.2

Click to expand...

If your target pH is 6.2 and the pour thru is dropping 1.0 pH unit, then why not try 7.2 going in, hopefully so it only drops to 6.2?

Looks like it was a bacteria or fungi problem. I hit it with a heavy dose of enzymes I had laying around and now the ph is stable and the plants are eating again. I normally use peroxide since it's much cheaper but the enzymes are just as good and they don’t mess with organics since I’m using fulvic acid.

You might have the same problem as me simpleleaf and since you're growing in soil you should use enzymes. I'm using this brand called Enzymes komplete natural cleaner the dose is 7-8ml per gallon.