Stem Rot, Nutrient Issues?

[zbuffered]

Hi all, I'm a new grower trying to manage a garden of about twenty plants and 1500 watts. It's proving to be an interesting and perilous journey. Here are some of the biggest challenges I face today:

I have several different strains of plants (Skunk #1, California Orange Skunk, Aurora B) that are growing in a rubbermaid bubble bucket. The plants are over a month old and look healthy, however some of them are exhibiting the following problems:

Stem Rot. Several of the stems have narrow bands around the base of the stem that have turned brown and look thinner than the stem of the rest of the plant. The plants (one in particular) look more and more precarious above this obvious weak point, but above it are healthy, growing, and vibrant. Previously, one plant that was about a month older died suddenly when the stem, which had rotted in exactly the same fashion, snapped. I see some algae on the hydroton rock.

Leaves dying. Other plants have lower leaves dying. They are 5 weeks and have maybe six nodes, and on average they've lost leaves from the lower two. The leaves are yellowing, curling up, turning brown, and drying out. Specifically the Aurora B. Strain and the CA Orange. I'm using less than full strength nutrients and when I had this problem with an Aurora B. before, it almost died and today is about 4" whereas the Arjan's Strawberry Haze plant that is it's sibling is several feet tall and well along into flower. Other plants are exhibiting problems less severe, with lower leaves dying. So early in a plant's life, could this be caused by too much nutrients? Should I further lower the nutrient levels?

Problems cloning. I've taken about a dozen clones now and only one has rooted. The rest have lived for quite some time but have simply refused to grow roots. My favorite is a little cutting that has lived now for two or so weeks without my watering it's leaves yet has no roots coming off of the stem. I want so badly for it to take hold of the hydroton and venture down!

My grow room varies from 60 to 70 degrees and the humidity ranges from 45-55%. I'm pretty much just using General Hydroponics and following the directions on the side, though once again the 5 week olds are on half strength due to my fears about the leaf issue.

Any and all advice, especially on the stem rot issue, is appreciated.

[SmknVTEC]

Yo man,

First problem I see is that you are growing multiple strains in one reservoir. This is generally a no no because each strain requires different types of nutes, conditions etc. Some may argue this point but, if they have been doing this successfully, they should consider themselves very lucky.

What you are describing sounds a bit like damping off and this is almost always fatal. The key is prevention. One should sterilize the hydrotone between every grow as well as all the equipment. The reservoir of nutes should be dumped and changed every week. Speaking of nutes, what is the PPM of the mix? Also there has been zero mention of pH which is the number one most important factor when growing hydro.

Your temps get to low. If the ambient air gets to 60 degrees unless you have a heater, the reservoir water gets to 60 as well. This is about 10 degrees too cold from what it should be at.

Can you take pictures of the bad stems? A picture speaks a 1000 words.

As for your clones who knows? You would have to describe your entire cloning method so we can see what is going on.

[zbuffered]

Thanks for the advice. You've given me a direction to go in improving things... I'll do some cleaning and turn up the heat in there. And hopefully soon, pick up a TDS meter.