i still think you are having over watering problems.
have you ever actually measured the amount of water you are using with each pulse and the precise amount of medium you are using?
the roots plugging the drains before your switch to the 80 mm drains are a result of running too much water through the medium too often, causing the roots to follow a channel.
i'm sure you are getting some dispersal but when one part of the medium is always wetter than another part the roots will tend to follow the wetter pathway at the expense of lateral dispersion.
a properly operated wave pulse is applied in small amounts frequently. amounts small enough so that the wave is just "sent" through the medium instead of "forced" through with a lot of excess water.
i'm not having a great day so i'm not sure i'm saying this right but the pressure from the top, the input, needs to be relieved before a lot of water builds up in the medium.
relieving the mass of water you have just applied of the propulsion represented by a sustained input of water. relieving it immediately after application but before the water reaches the bottom.
just a shot at a time, frequently.
this allows hysteresis to occur in an already wet medium. hysteresis is the lag time allowing dispersal to occur.
even dispersal.
water microscopically "jumps to wet" and resist going into dry.
hydrophilic and hydrophobic.
this does not have to be a completely wet/dry scenario as the water will still tend to run to areas that are just simply more wet than other areas. this is because of cohesion.
i don't know, it may be something else entirely but considering the fact that you are not measuring the amount you are applying i think it's a good guess.
you can't make accurate corrections if you don't know the starting point.
but you should be using the bloom formula by now, too.
i'm at a big disadvantage trying to diagnose problems at long distance.
back when i ran coco in 3.5 gal buckets with a single tailpiece i was doing a wave type pulse.
i experimented a lot but for a while i was applying 4 oz's every 15 minutes. grew beautiful plants
just a little shot that kept the medium from drying and concentrating salts and refreshed the gases in the root zone.
i also used 32 oz's every 30-45 minutes successfully. grew beautiful plants.
you need a better timer.
the discussion on big john's thread about the forms of nitrogen would only be important to you if you are running ro water or extremely good water like john is.
it's either a mechanical problem caused by improper watering or a chemical imbalance caused by everything that's in your res.
there's nothing else in this device.
just because one person gets great results with a nutrient product does not mean that you will. again because of the differences in water quality.
i know that i have never, in the last 4 years since i began playing around with these ideas, lost a plant for any reason due to a mechanical failure or nutrient problem.
and if you look back through the threads i have done here you will only see healthy plants.
i have had slow drains in the grow where i used the larger containers with single tailpieces but i realized it was happening and took steps to save everything.
i wish i were there to help.
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