Problem with some roots turning black in S/H

[Linnie]

i've been using S/H for over six months now and had great luck.

I just discovered one Catt and one Phal that look very healthy, have great aerial roots on the Phal but I noticed one root with a dark end on both of these plants. I went ahead and unpotted to see what the problem was and discovered some healthy some mushy roots. Here are the specifics.

One is a Lanceps Ft. Caroline and I planted it in april. It looked nice and healthy but did have lots of algae on the sides. I used Physon several times to try and clean it up. Today I noticed that one of the root tips was black on the end. When I unpotted it I found many of the roots soft and mushy. See the pix.

Seeing this made me wonder about my Phal that I planted about the same time. Its a Phal Lippergrass "Krull Smith' The aerial roots on this one are incredible looking nice clean and I thought, healthy. I did notice that at the point where the plant goes into the agra, it looked dark. The Phal was not growing straight up and kept tipping itself. So I unpotted this and found a mixture of very healthy roots and mushy soft roots with some of them looking black. My camera just went on blink so can't take pix right now on that.

Does anyone have an idea what might be happening?. I am using Prime Agra and planned to change a bunch more over the prime agra but now I wonder. Why would the arial roots be so healthy and firm and the roots in the mix be all soggy??

Other question. I've went ahead and used bleach on the small plastic pot and I am soaking the prime agra in Physan and I poured a mixture of Physan over both orchid plants. Should I pitch both pots or do you think the bleach will take care of it, and what about the prime agra??

Thanks

I grow both plant outside east coast of Florida on the east side of the house in an "unscreened" porch. I'm really a newby to orchids and just give both regular city water and have just alternate between a balanced fertilzer and then bloom booster once a month. I just follow the label strength and use a little less than stated.

I have to admit I haven't been faithful about flushing everytime I water, and maybe that is the whole problem??