Be sure to read Stinky's sticky:
http://boards.cannabis.com/plant-pro...hy-how-do.html

I would recommend to get a digital Ph pen like this:
Amazon.com: Milwaukee Instruments pH Pen, PH600: Kitchen & Dining

For now, yes get the fish tank Ph test drops and find out what's your tap Ph. bring it to normal (6.5 ish) and flush and test the first runoff that comes out. If it's brown colored let it sit so it's a bit more clear and test it with your fish test kit drops. The color may be a bit skewed but it'll still give you the ball park. Yellow is way too acidic and blue is way too alkaline (base). Adjust it more in the opposite direction and flush like crazy 'til it's in range. Skip watering 'til they are almost dry, water normally (with about 10% runoff) and check again.

With the 24 hour lighting I gather you're still on veg cycle. You do realize the HPS is for 12/12 flowering, yes?

Keep us posted. Keep up the great work. :thumbsup:
Ocotillo Reviewed by Ocotillo on . Help please turning yellow fast Hello I am new to this and am having problems with my plants. I am using sunshine mix4 and NSR greenleaves grow juice and boost juice once a week. The plants are about 8 weeks old and are just now starting to show problems. My lower leaves are where I first notice this and the leaves are tuning yellow with brown spots. My first guess is mg but the stems and veins are really purple/red. It is now getting worse and moving up my plants turning more and more leaves yellow. The first ones that Rating: 5