I grow on grodan libras 100cmx15cm. I got realy big problem i soke all slabs before planting and startblocks in 5.2 Ph 1.4 ec and get nice slabs 5.9-6.4 ph level and 1.3 1.4 ec. In watering tank give 5.7Ph - 5.8 Ph + EC 1.3- 1.4 give them B`cuzz A&B nutrients + PK 13-14 (50:50) all time - everything goes good but in second week of flowering lot of slabs start rise up EC, PH has good 5.9-6.6 Then but EC rise up to 1.5 - 2.2 I rinse slabs with PH 5.8 water without nutes. And after rinsing make back in tank 5.8 ph + ec 1.3 2 days all mesures has good but in third day in allmost half slabs ph falls down to 4.3-5.4 ec is 1.2-1.4 Tell me please if is some way how to get back good Ph level i see plants are suffering. I try disconect water for 24 hours in hope the ph will rises up but it doesnt help get even worst. Now watering again with 5.8 ph get back +/- 5.8 Ph in slabs but now after 2 days again in several slabs i see ph is 4.3 4.5 4.8 5.1.... What can be problem ? Now plants is 2 weeks + on 12/12 regime. If sombody can help how to do like that ph didnt fall, i will be gratefull ! P.s. Please if somebody know how tell me PM or here, plant are suffering (( Thank you for support !