Thanks for quick replies guys

Quote Originally Posted by Daddynobucks
IMHO, with that many plant sites and that small of a res. its gonna happen.

also used GH 3-2-1, 1-2-3 for quite a few grows initially in a 3" tube system with small res. 18 gal/28 sites.

went to buckets with 6" netpots and 20gal/6 plants still had the problem you have,just not as bad

SO, checkout Latewoods legacy a sticky post. it uses a whole different GH reciepe, and it works much better
the Ph runs more like it should. stable until nearing a nuit. change,then it starts changing about 0.1-0.2 units daily

Do you make up with Ph water or a nuit solution?

Read Latewoods legacy
So your PH drops into 4.5 range within 1-2 days also? Changing to a bigger res helped? If so, how much? What is your PH drop like now? What size res should is good for 12 plants that end flower at around 2' tall??

The system is topped off with regular tap water @ 7.0 PH and less than 100 PPM.

Quote Originally Posted by Dutch Pimp

Does the recipe work without a reverse osmosis filter? Economical situation is bad and they look to be around $300-$500

EDIT: It seems strange to me that I could not find any threads anywhere on this problem. I must of googled every possible variation on this problem, searched endless amounts of threads, and found nothing concerning this problem. Could it really be something as simple as the res is too small?
killyjelly Reviewed by killyjelly on . Low PH problem First time poster, Long time lingerer :p These problems have been occurring for a long time and I have never found a solution so the plants have suffered for some years. :( Right now there are some plants growing in a homemade tube system almost exactly like pictured below. The ingredients consist of PVC fence posts, PVC pipes for the manifold, plastic reservoir, PVC glue to hold the manifold together, Plumbing grade rubber tubing to connect the Rubbermaid top-off reservoir, a pump, Rating: 5