Nutrient Salt buildup or Mold on Rockwool?

What's happenin Rollitup people? Total newjack grower here. Definitely want to give a serious THANK YOU to this entire community; don't know HOW I would've made it thus far without the insane amount of info available here!! Roseman, Potroast, Mogie, GardenKnowm, etc.; I simply whispered your names to my stressed and depressed babies, and they are comforted... So, yeah, I'm a newb. I've done my reading, and will never stop. In the meantime, can anyone tell me about their experiences with white residue on the TOP of their rockwool cubes? I've read the MOLD horror stories, and perhaps need to accept my failure, but... Though I've cerainly made every mistake in the book, and then some, using this forum, my grow has stabilized, with new and healthy green, and nice roots. Temp,humidity, res temp, ventilation, nutes, and ph are all settling down nicely. Using the Bubbleponics system, 3 weeks in from good indica seeds, 250 watt 65K cfl w/batwing reflector, numerous other cfl's are not being used yet, as they are still VERY small due to all my mistakes (basically, some burns from my attempts at Foliar spraying, which I'll NEVER do again, at least until I'm more experienced, and my light being too close). New growth is good, and other than the lower damage, things are looking fine. At full strength Stealth Hydro nutes, with superthrive and H202, RO water, 2 airstones and dual outlet air pump. Yes, I know - it's somewhat ridiculous to ask all of you for ANY help without pics, but please bear with me, will have dig. cam soon. The only other info I can give which might have some relevance, is this: The ONLY plant with NO white res. on it's rockwool cube is the SICK one. Germed WAY too quickly, and stretched for light in about 2 DAYS!!, so, she's been sick since the start... Yet she's the ONLY one without the white stuff on her rockwool cube. Am I being naive? Wishful thinking? I could only find some basic mention of mineral salt buildup on rockwool, so, if it's out there, please forgive me and my RAMBLING, and point me in the right direction. ANY info, help, criticism, newb jokes, are WELCOME!! Thanks again to all who take the time to be a part of this forum. YOU GUYS ROCK. By the way, my thumb is far from green, and I'm a mechanical IDIOT. Bubbleponics is the real deal. If I can do it without killing everything the first couple days, well... there it is. -Guitar Player, swm looking for LOVE and some beautiful TREES

Well, ahem, you appear to be a nice guy, but, I'm not available.

And your plants sound like they are doing fine, and will continue to grow nicely. Healthy new growth and white roots are precursors to a nice yield. And some white stuff on the rockwool after 3 weeks is probably nothing to worry about. Have you tried scraping it off? That may give you a better idea of what it is. It's probably mineral salts, like you said. Even if it's mold growing on the wet surface, it won't hurt your plants. With the H202 you shouldn't have any stuff growing on there.

It sounds like you've got a good handle on what you're doing, and will continue to keep an eye on it.

HTH and welcome to rollitup

I am glad you asked that question! I have been noticing the same thing on my rockwool cubes and was wondering the same thing! Hopefully it is just buildup instead of the dreaded mold!

i just noticed the same thing also its nuet buildup i just stop adding nuets when i see this happening, it starts burning the plant if you keep adding more