powdery mildew, mold or salt buildup

[shift00420]

Whats up farmers? This is the first run with this hydro system & Im having a little problem well not a problem yet i dont think. I have noticed white stuff on my 4x4 rockwool cubes. my system is a recirculating NFT system using 5 gallon buckets, 6" net pots filled with clay pellet around the rockwool cubes. I have drippers dripping onto cubes & 4" coco covers over rockwool.
Anyhow the plant look great no signs of stress so im really only concerned about the white shit building in the cubes & stones. There are no signs of powdery mildew on the leaves anywhere. Its just on the rockwool & stones right now. I thought it might be salt build up but the stuff wipes off rather easily. I'll try to post a video or pic in a moment. thanx in advance.....

here is a pic of the stuff on the rockwool & on the hydrostones

 

[sealed138]

Looks like salt buildup to me. Try running drip clean if it gives you any problems.

 

[shift00420]

Honestly thats what im hoping is the case. I will give drip clean a try.

 

[bobbybrown]

It's probably a little bit of salt buildup and mold. Not Powdery Mildew.

 

[bigloudvtwin]

Cover up your individual sites with mylar circles or something similar to keep evaporation down. What happens is the nutrients stay there after the water evaporates EVERY TIME you feed. My hydroton was doing the same thing til I covered it up. It got so bad that it was actually starting to nute burn my girls. Good luck

 

[shift00420]

Thanks bigloud ill give that a try

 

[AmityDWC]

I run 6 DWC in 10 gallon coolers" to keep the water temp right where I want it without the need for a chiller at all"; anyways I experience the same problems with salts and algae build up and the best thing I have found is to keep the light from hitting your pebbles or rockwool with some kind of cover. I use panda plastic and put it with the black side down and the white side facing up.

 

[Greenjean]

I also seem to get a little of the buildup on my Rockwool, I do the same as AmityDWC, and use plastic to cover up the tops of my blocks. I will hold them in place with toothpicks and works like a charm.

 

[woodsmaneh]

Cover the cubes with some sand or go to the dollar store and buy some stove burner inserts. There round aluminum curved plates cost 1$ for 10 and come in different sizes. Cut some black and white and cover.

Salts build-up.

Drip clean is good.

I make sure my blocks are deep enough to be covered by the hydro-ton, no more problem.