Algae on rockwool??

[Stan]

If that's an indoor plant what light are you using? You will still need to cover up the rockwool so it doesn't get any light at all or you will have the same problem.

First try cutting off the top portion of the rockwool if you can get enough off and it has no algae you would be good with that. If you can't get the algae off then you will have to slit the rockwool in the middle and get the plant out. You might lose a root or 2 but as long as you have a root or 2 still on the plant it can survive.

[HydroBill]

It's a duel bulb 'H' fluorescent fixture. Each bulb puts out 6500k at around 3400 lumen, so 6400 lumien total output. I got it because it's compact and I thought would be perfect for a single bucket, but I'm kind of regretting that now. Looking around, the bulbs are hard to find and more expensive than T5 or T8s. Live and learn, I guess.

Just in looking the algae seems to go down a quarter to half an inch or so. I'll try spiting it open and getting the little guy into a new rockwool today. It's too late to move it outside and expect it to produce, so may just keep it going inside and see what happens.

Thanks for replying Stan. If I decide to keep it going, I may start a thread in the blog or setup forum and keep y'all updated.

[eronjonson]

the algae is just an aesthetic problem really. if you dont like it, just bury the rockwool under enough of the other substrate to cut the light off of it, or just enough so you dont see it, the buried stem will send out roots, which is actually really good for tomato plants, and you can even pinch the stem before you bury it enough to just hear it crunch, that will strengthen the stem, but make sure it still stands up or else it will lignify into a bent position.

id go ahead and stick it outside too, youll get a ton more light, and they dont mind being in the water a lot more deep than what you have, just as long as you have good aeration to the water, aka an airpump with a hefty airstone in that bucket.

[HydroBill]

Thanks eronjohnson. I thought it might be harmless but wasn't quite sure. Drip systems seem to be pretty popular and I'm sure they get plenty of algae on the exposed substrate.

As for sticking it outside, this is an experiment to see if I can have fresh tomatoes during the winter. I want to make a go with it inside under lights. As you can see, it's doing quite well under the current ~6400 lumens right now. I'm planning on getting two two tube T8 shop fixtures within the next week or so and placing them vertically on either side. This will add an additional 11,000 lumens and distribute it more evenly over the whole plant. The whole mess comes to around $45.00 plus tax at Home Depot. Like I said before, I'm not happy with the price and availability of bulbs for this specialty fixture I bought. I want to replace it anyway, so may as well start now, and almost doubling the lumens at less than half the cost, I can't not do it.

[fintuckyfarms]

I just use some craft foam and cut out a circle large enough to cover the square and cut into the center and make a smaller circle to go around the stem. Then mist with some hydroperoxide to kill the algae. Craft foam is really cheap and comes in lots of colors. Usually 4 for $1 at a craft store like Michaels.

[Davidj]

Hello, I have just started with hydroponics as well. Also I have just started to see algae on my rockwool cube as well. I don't think algae is bad for the plants, but I think the algae is going to eat your nutrient solution.