Your blossom end rot is probably caused by a shortage of calcium in the nutrient or a root problem effecting the plants ability to take up calcium. If it is a shortage, using calcium nitrate is the best solution. If used carefully, calcium chloride can be added to the nutrient or a solution containing calcium chloride can be sprayed a couple times a week on the leaves before the tomatoes begin forming.
As for the peppers, I would get a 10 or 15 power magnifier and look for mites on the under side of the effected leaves.

Norm

Hey Penjing -

Are you sure its "soft water"? For example; we have low water tables here in AZ, and our water is hard. If your pH is too high... a lot of important micro-nutrients are locked out. A high pH is usually associated with a high reading of CaCO3 (calcium carbonates). There are cheap methods to bring these kinds of things into homeostasis, or balance.

If you could contact your water company and ask for the annual report, or test the water yourself and post the data we may be able to help out There are just so many things that could be at play here.

I.e.; Res temp to high, Not enough nutrients, Plants could be drowning, Root rot, Roots drying out, etc. etc. Lets start with you water and methodically eliminate possibilities. Sabes?

Thanks for input. Local water co. told us our water has been soft for quite some time due to lack of rainfall. Water report showed PH to be at 7. TDS at 60. I also checked for insects with a 30 power scope but none visable. Early in the year we had aphids but sprayed them away with a hose. I've been growing tropical bonsai for 30 years and never had these kinds of problems before. This is my first try at hydroponics. Plants in soil are doing same thing. Top growth shows problems first even on shrubs out in the yard. Bottom leaves remain fine. Have given up on peppers. What really perplexes me is that one plant does OK but the one beside it gets really sick. I'm thinking that our water is leaching all nutrient away from roots. I was thinking of using water from dehumidifier and adding calcium and magnesium or would water from our Japanese styled pond be better? Thanks

Sounds eerily similar to a water softener set-up, where the calcium ion is being replaced with a sodium ion. Are you in Coastal NC, or relatively close?

You said 60ppm in TDS; can you be more specific as to exactly what that number represents? I think you have the right idea as far as the leaching is concerned. You may need add calcium and mag. if that number represents sodium. The problem will be measuring the right amount so you don't over do it. Do you have a TDS meter?

I would check the water from a dehumid if possible before I used it, but that is me. Then again, I'm sure if you searched the net you would be able to find someone that has used it before. I differ to them, because I never have. You can get a pool pH kit for like $6 bucks and TDS meter for another $40 online.

People use pond water in aquaponics and have great results. However, I'm not well versed in the use of pond water in hydroponics. I have seen the aquaponic set-up at the Univ. Of Arizona and they have all kinds of filters and other things inline before the water actually reaches the plants.

Too much of any one thing is usually bad. Balance is what we are after... like Bonsai. Fish poo is probably really high in nitrates and that may be bad or good. I don't know enough to tell you. Algae is generally not a good thing when talking about hydroponics, or plants in soil for that matter. You would have to research this route in pretty good detail...

Bottom line, I would go talk to some nurseries in your area and ask about what they are doing to correct this problem.