What method did you use to get the ph of your runoff?

What's your water ph going in? If necessary, I strongly recommend any of the phDown products specifically for agriculture or gardening. There's nitric acid, which is not a good idea later-on when trying to flower 'em, there's sulphuric acid, and there's phosphoric acid, which I use.
In a pinch you can lower the ph using vinegar or lemon juice. Aim for a water ph of 6.3 to 6.8ish. I've heard thay aren't especially good long-term, but I have never done so myself for more than a few days. (till my acid is delivered)

There's too much nitrogen in a compost (or garden mix) and no way to flush it either. Again, I strongly recommend you get some container potting mix with perlite in it, and transplant asap.