Runoff Ph Question

[mickeymac]

I have some bubba kush clones that I planted roughly a week ago. Some of the plants are starting to show problems like leaf edges curling up, and some brown/yellow spots on random leaves. I know this can be associated with heat stress but I have excellent air movement and the plants are over 3 ft from the lights (1000w MH). So I decided to check the runoff ph to see if there was some lockout of salt buildup going on. The water going in is RO water with PH of 6.90 the runoff coming out had a PH of 5.21. This seems very low to me but I have never had this problem. Also my PPM at EC x 700 are coming out maxed at 2520. Seems way off to me. Will a solid flush get these numbers back in order or do I need to add lime to the soil? The soil is a 3 part fox farm blend and they have only been given nutes one time (fox farm grow big and big bloom recommended amount).

mickeymac Reviewed by mickeymac on 03-19-2010. Runoff Ph Question I have some bubba kush clones that I planted roughly a week ago. Some of the plants are starting to show problems like leaf edges curling up, and some brown/yellow spots on random leaves. I know this can be associated with heat stress but I have excellent air movement and the plants are over 3 ft from the lights (1000w MH). So I decided to check the runoff ph to see if there was some lockout of salt buildup going on. The water going in is RO water with PH of 6.90 the runoff coming out had Rating: 5

[perpetr8r]

Hey Mac,
I too use fox farm nutes. Going on my second year growing with a 30 day perpetual harvest so I can speak from some experience for you. If You fed them the "recommended" amount for their first feeding, you fed them too strong of a solution. You havent done any irreparable damage. Fox Farm nutrients are very strong, it is recommended to cut their mixture amounts in half, at least until you see how the plants can handle it. Most plants cant handle a full dose of FF. I adjust my ppm's according to the plants progress. You need an ec meter to properly measure the strenght of the nutrient solution. Just feed your plants plain ph adjusted water for the next couple feedings. That will dilute the strong mixture already in the soil and allow the plant to use it all up so you dont get salt buildup. Flushing is stressfull for plants so try to avoid it if possible. feed them half strength and gradually mix to full strength ( i use full strenght during the last four weeks, the cha ching mix is a weaker ppm) Also, make sure you dont feed every time. Feed, water, feed, water... Also, don't stress run off ph. Yours is low and the ppm's so high because you over fed them and the plant cant use it all. The plain water feeding will help fix that. Just make sure to adjust ph after adding the nutes to the water. As long as you put in the right ph and dont over feed.. all will be well

peace.

[mickeymac]

Thanks alot man, I totally agree. Very helpful response.

[perpetr8r]

Any time mang :P