autoflowing big buddha blue cheese in wilma 4 ph problems day 54

hi everyone i was wondering if anyone could help im having ph problems I have about 3 - 4 weeks left depending if its 10 to 12 week strain My EC is stable just my PH dropping all the time and im at a loss at what to do next

yesterday
I filled up rez set my EC to 0.8 and PH said 6.2 that was at 6pm by 12am EC would be 0.8 but ph would be 5.8 by 1am it dropped to 4.8 still stable ec but it drunk 10 litres so because ec was still stable i topped res up with 10 litres of same strenght feed that they had at the last res change it brought Ph bk up to 6.2 but with in 2hrs ph dropped again to 4.8 but this time plants only drunk a few litres of water so i emptied some water out and added plain water to bring ph bk up again and left it over night to see how it goes.

Today

Checked them at 1pm and it was bk down this time PH was 4.3 but this time ec had slightly dropped to 0.7 so i did a whole res change again and by 6pm it was bk down again to 4.8 but still ec stayed 0.8 this time so ive emtyed res and put plain water in with oxyplus @ 1ml litre i was planning on leaving this for 24 hrs to see if that would help but after an hr its almost drunk half of res and looking like its gonna need another changed before i go to bed. I dont think Ph dropping is down to root rot as ive checked all the roots and there a lovely white colour and they dont feel like theres any slime on them at all. Res temps are 22c.

ive checked ph pen in calibration fluid just in case it needed recalibrating but it was spot on so its not that.

i can either continue feeding pk booster for another 2 weeks doing full res changes 2-3 times a day which means wasting a load of nutrients and water.

Or i could just switch from my shogun warrior pk 9/18 to the SHOGUN Dragon Force for a week to ripen up the plant and just finish the grow early just to get it down and go bk to 1 plant per system. I knew there might be chance id run in to probs cus of using 4 seeds not cuttings the wilmas was designed for plants from same parents really so they all feed the same and roughtly same ph.

if any one can offer any thoughts or solutions much appreciated

rizzla2008

Hi everyone just a small update the 4 plants have been on 25 litres of water with just oxyplus for 24 hrs and ph as only dropped from 6.4 to 6.0 since it was done last night and they have drunk roughtly 15 -20 litres in total usually when waters this low ph would be 4.8 at least so not sure if its vitalink bringing ph down or the new shogun boost nutrients im using because its stayed more stable over night with out having feed or if its just somethink im doing wrong im gonna fill rez up with some more plain water and just add some more oxyplus see how they are tonight and hopefully by then someone in here can give me some advice much appreciated rizzla2008

ok been to growell to try and sort this ph problem out while i was there they phoned the company that made the wilma system to ask them if they come accross this problem this is what they told us over the phone

right - apparrently, the reason the ph is dropping so much is actually a factor of how well your plants are performing and how much of the PK they are uptaking.
so that's good - it indicates that you have very good plants at this stage.
The effect should be temporary and using silicon will significantly help buffer this effect. it's also a factor of how soft your water is - stopping aeration in your standing tank will again help reduce the effect. top up res with ph water adjusted to 6.6 when you mix, then as the pH falls away, use dilute silicon to re-rasie that value it should keep it more stable for you and stop u having to throw away last 10 litres when it goes lower than pump.

so they told me to add the Silicon first, & pH adjust to 6.5, then add your nutes & boosters, the silicon will help buffer the pH

so im gonna see how the girls do on this silicon and let u all know in the next day or two in case it helps others out as ive seen a lot of people with same symtoms on other forums so could be helpfull i didnt relise silicon raised ph either till he told me on phone.

anyway thx for popping in

rizzla2008