Slight curling and yellow discoloration

The leaves on my plant are curling slightly at the edges, and are getting slight yellow areas of discoloration around the tips of the leaves.

Hydro constant flow, pH 6.3-6.8 usually. Pure Blend Pro Grow nute (sprayed on foliage about 3 times a week.)

Under a 400W HPS.

Sorry about the quality of the pics, only camera I have is on my phone...

Any help is greatly appreciated. :sun


Are they curling under. Hard to see anything in those pics. Typically if the leaves are curling under its a nitrogen toxicity. Flush em with plain water and 1/8 strength nutes and see how it goes.
Sorry about the quality of the pics. My nice Canon 1D got stolen a few months back or I'd be using that.

Leaves are curling up around the edges.

Temp in reservoir was like 80F this morning, Air temp is around 80-85 w/lights on.

Using Pure Blend Pro (Grow), dont have a nute meter but I'm adding 90ml of nutrient for a 6 gal res.

Attached some more pics. Hope these are better...

Thanks for the help, gonna lower the pH and see how that helps.


Premium Member
Your air temps arent too too bad.. 78 is ideal:) Temps will get worse once summer comes around, but for the moment you arent too bad. Without CO2 78 degrees is ideal.

Your nutrient temps should be between 68-73. At 78 you will get pythium. When it gets hotter it will get worse. A temporary solution is to attach a small computer fan to the lid of ressy so it blows air across the surface of the solution:) This will drop solution temps about 5 degrees on average. That will help you there for the short term. The only disadvantage is that the solution level will drop faster, due to an increase in evaporation, therefore topping off more frequently will be required.
You can also get a Ice Probe
Them lil gimmicks rock and will help considerably:)

Yup your PH is way high bud...
Your PH should be between 5.5-6.1 hydro...6.3-6.8 for soil.. When you say your pH is 6.3-6.8 usually? Do you have big PH swings? Im thinkin so when you say usually:)

PH swings are a huge problem.
Heres what you need to do.
Fill your ressy with r.o. water. Adjust the PH of the plain water. Wait 12 hours letting the solution bubble/mix. Then add your nutrients. (You can start feeding this to the plants at this point, if you cant wait). 12 hours after adding the nutrients check PH and adjust one more time if needed. Adjust in small steps. My 40 gallon ressy's only take about 20ml of ph adjuster each to stabilize it. The key is to allow the ph buffers to do their job before you add in more.

If you correct that stuff you should be well on your way:)

Hope this helps a bit for ya:passingjoint:



Premium Member
Also Arrows, I would bury them rockwool cubes in the hydrotron.. Ya dont want your roots exposed to the light. It will also help prevent against green algae growing on the RW cubes.:big_boss:

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