I use masterblend with excellent results.
If ec was 4.5 i would think the plants would react in a day or two. Possible wilting, leaves folding down along the midline, darker than normal green.
Why do you think the ph is moving?
The only explanation for high ec in the morning is the salts may not have all been dissolved until morning, which would show an increase at that time.
I would do what you know works, and fix it all when you get back and have time to sort it out.
|