Rockwool ph/ ec rising

For the people who have experience with growing in rockwool, is it normal for my runoff ppm/ ec / ph to rise?
If so, what should I be looking at for a normal/ acceptable range?
I just started some rockwool clones in the 6x6.
I originally had the cubes soaked at 5.8-5.9 ph and around 1.6ec.
When I checked my runoff today (it’s been 1 week since I soaked the cubes) my ph was 6 and my ec was 3.4. Is that normal?
I thought I read that if the ppm/ ec shoots up higher with runoff than that means that there could be salt build up. Is there any truth behind that? If so, would that mean that my rockwool as a shit ton of salt built up? I’m not seeing any on the cubes tho.
I haven’t had any clones droop from being dry or anything that like that.

How are you watering them? hand, drip, flood? Rockwool should be top feed at least once every day to refresh the solution in the cube. salt buildup will start to occur once the block starts drying. If your blocks are too high you can flush them with plain ro water and refresh the cube with new solution. Thru alot of trail and error with high ppm and high ph in rockwool, this is the conclusion I've come to. I've also had my plants show ALMOST no signs of ph or nutrient burn/deficiency other than Nitrogen toxicity.

RocketBoy said:

How are you watering them? hand, drip, flood? Rockwool should be top feed at least once every day to refresh the solution in the cube. salt buildup will start to occur once the block starts drying. You can flush the block with plain ro water and refresh the cube with new solution. Thru alot of trail and error with high ppm and high ph in rockwool, this is the conclusion I've come to. I've also had my plants show ALMOST no signs of ph or nutrient burn other than Nitrogen toxicity.

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I have been hand feeding top feed. I have a floraflex cap on it and have been watering it that way. Each plant is taking about 1000-1250 ML of water every 2 days. On the second night when they come on, I have to water again.
Right now dealing with some electrical issue with my reservoir. Trying to set that up to top feed in that time span/ shorter (as needed).
I went ahead and flushed it with tap water, but ppm comes out to be like 80 out of tap. I’ll eventually get RO for it.
I will be getting an extension cord to bring to another room and I’ll be able to do it. They seem happy for the most part. Towards the end (last 3-4 hours) they get a little sad, but that’s what the res will do. But yeah. So far so good I guess.
How long have you been growing in rockwool?

About a year with rockwool but on a drain to waste system (trying out resirculating as we speak), Im a pure hydro guy (NFT). 80 ppm out tap is fine but I would still buy an RO DI system just to have 0 ppm, which makes things much easier to control. Ebay has them cheap (around $50) and they work.

RocketBoy said:

About a year with rockwool but on a drain to waste system (trying out resirculating as we speak), Im a pure hydro guy (NFT). 80 ppm out tap is fine but I would still buy an RO DI system just to have 0 ppm, which makes things much easier to control. Ebay has them cheap (around $50) and they work.

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I have access to one, but carrying a 27 gal res of water back and forth would be a pain lol
I’m doing the drain to waste too. How are you like the two growing styles? Anything you like more or less with one or the other? Growth rate?

NFT on a timer blows rookwool out the water, the fast root and plant development is not even comparable, it's almost like running a true aero system. I would still run rockwool over messy coco or any other soil/less mix. Rockwool is a bit finicky but once you get it dailed in they take off.