Quote Originally Posted by bonbon
did you prepare the rockwool first?you must stabilize the cube's and block's ph before their used,by soaking them in a ph solution of water adjusted to 5.0 for 24HR's before you use them,or else they will be too alkaline for the plant's....bonbon
No, I did not. I heard of the alkalinity problem with rockwool. I also know and witnessed some who never stabilze their rockwool and do not have a ph problem. However, for them, like me, they do not use an active hdro sytem, rather we hand water. One inherent problem with hand watering is the tendency for the raockwoll to build up nutes, salts, and become acidic. Whereas the acidic problem may be appearent in a more netrual medium, in alkaline rockwool the " acid problem" associate with hand watering serves to neutralize the rockwool "alkaline problem". However, the rockwool alkalinity problem may still be prevelent at least initially until multiply nute feedings have brought down the ph. Since I handwater, rockwool alkalinity has not been a problem except when sprouting seeds od I would assume cloning. The reason being that during these earlystages very little nuts solution is used to counter the rockwool akalinity. This doesn't seemed to be a problem at later life cycles when using blocks and slabs because much more nutes are used to quickle nuetralize the rockwool. I recommend that when hand watering, one needs only to stabalize starter cubes for seedlings or clones, and not worry about the big blocks and slabs. A tell-tale sign that the rockwool is too alkaline will be a slimey, geasey feel in the water and rockwool. Thanks for the tip. Now some good news. My plants are recovering. The problem seems to indeed been the keep the plant either too close to the lamps of for too long. I moved the plants to the widow sills for a full day sun, and no more. They slept in the dark at night. I also gave them a does of nute because of the lime green color. No they a doing beautifully. Dark green color has returned and leaves have no more curl.
mahatma Reviewed by mahatma on . Can too much light hurt seedlings? I started seeds 3 weeks ago in rockwool cubes. After sprouting, I used a weak nutes solution for the seedlings as recommended by the manufacturer (4-6-7 @ 1 tsp./gal. of water), kept seedlings at around 1- 2 inches from floros lamps, 24 hours /day except on sunny days when they were moved to the window sill. I fed and watered the plants by hand, flushing the rockwool with nutes solution at least once per week and watering as needed with just plain water between feedings. At two weeks old and Rating: 5