I’m using FF Happy Frog soil with around 10% perlite added by volume. I have an indoor grow tent and utilize two self-watering pots with a drip irrigation system. I’m using the ILGM nutrients and measuring the recommended amount of fertilizer before adding it to the reservoir, but the runoff numbers I’m getting are way off and I need advice. The following are the most current readings taken. I have an Apera instrument
Pot 1
pH: 5.25
Cond: 5.92 EC (mS/cm)
TDS: 4.21 ppt (trillion?)
Pot 2
pH: 5.12
Cond: 5.82 EC
TDS: 4.10 ppt
Also, do I need to flush the plants before moving into the flower stages so that correct stage 3 nutrients are all that is present? In other words, do I need to empty my self watering pots and start with all new clean nutrient mixture?
pH is on a log scale. ~5.3 is extremely low for a soil grow. You have a salt buildup. Happy Frog will revert to a pH of ~6.5 with a good flush down to ~300 PPM.
A product like Fox Farm’s Sledgehammer or Florakleen makes a flush more efficient.
Interesting to see this. We’ve not seen evidence that Bergman nutes were particularly salty. It might just be a case of overfeeding with the high PPMs. The EC should be ~1.0.
Those numbers mean your meter is converting EC to ppt by multiplying EC by 0.7 (albeit a bit inaccurately). Total dissolved solids are reported more often as ppm, so you should see if the Apera can display those units, instead.
You should also check to see if it can switch to the US standard conversion, for which 1 ms/cm = 500 ppm. That’s the default conversion on this forum.
Im not sure on the ppm numbers you have , as ppm is a solid number like 500 or whatever. But you ph is really low meaning nutrient lock out. I had tons of salt build up using ff nutes. But i also had a soil that maintained a ph of 7.2 no matter what i did. I currently use advanced nutrients perfect ph . Ive heard that when using ff nutes its common to flush before flower stage . Sledgehammer will help but its also another chemical added. But I’d definitely do a flush to with ph’d water to get ph back in range. Then slowly add nutes at 1/4 strength till you get to 900 ppm and work up to 950 ppm .
How do the plants look?
Im unfamiliar with ilgm nutrient lines but those ppm numbers seem really high
But if they are doing good then as far as when you switch to the flower nutrients, if it was me, i would just let it use up what’s in there just as to not waste it, and then just add the next mixture in or if you wanted to dump any remaining little bit out, it want hurt anything.
Should not have to flush as long as the plants are healthy and growing
The mixture doesn’t have to be switched exactly when switched to flower but at least in the first 2 weeks is kinda how I do it.
Aha. Turns out that “ppt” can mean parts per thousand or trillion. The correct interpretation is application dependent and the OP and I guessed wrong. Thanks for clarifying!
He still needs to switch the meter from the Australian standard to the US one. In US units, his ppm is 3007.
That’s still crazy high, of course, and a flush is surely needed.
I think the plants look good. They’re in their 5th and 6th week. I ended up flushing them, and then as Bluedream1 suggested began slowly adding nutrients until my numbers were where they’re supposed to be.