Ph

[GreenWeed28]

How important is the pH of the nutrient solution if the solution is regularly changed?

[Labrat]

I'm no hydro expert, but I would have said it was important.

Its not going to matter how frequently the solutions are changed if you're starting with the wrong pH.

anyone else?

[midnite toker]

The PH of the nutrient solution (water) is essential,if the PH is out then some nutrients in your chemical nutrient solution whatever brand u r using will be locked out.

You should try & maintain a PH of about 6.0 as at this level all nutrients will be made available to the plant.

If like me u r useing a liquid PH indicator(Growth Technology)then i add 2 drops of that into 1/2 a phial of n/s & hopefully get a pissy orange colour.

I hope that any of this can help u out, all the best MT

[NPK]

The most useful thing, IMO, you can buy yourself when growing hydro is a digital ph meter.

You can pick one up for £35 - £40. I bought the cheapest Hanna one for £37 and now can't believe I ever managed without it.

Here is a link to a chart which show the optimum ph for various nutrients.

I like to have my ph at 5.8 during veg and the stretch part of flowering (roughly the first two weeks). I then increase it slowly over the next 6 weeks with it finishing at about 6.8. This in theory increases the availablity of P & K to the plant which is what you want during flowering.

npk