weedmonster

Hello,

I measured the ph of my NFT tank yesterday and it was down to ph4. I know this is too low so i added some water which was NOT ph adjusted (my water is about ph 7.5) to it to make it up. It is now about 5.2. I have now ph up stuff, so i will add more unadjusted water once the plants have drunk a bit more.

Anyway, is ph drop normal? I thought that the ph only rose over time, maye im wrong?

Am I right in thinking that when the ph is left to drift between 5-7 (or something similar) this would be better than if it was kept a ph6 constantly, this would give the plants access to different nutes? But you wouldn't leave the ph at the wrong level for more than a couple of days?

Anyway, they were at ph4, and the last time i checked it was about 5 days ago when they were at ph6, and they still look healthy.

There are 5 plants in the pic in a NFT205 system under 250W HPS. - I know this is too many for my setup, but will remove males once i know which are males (i have clones rooting at the moment - hopefully - if they dont die). I'm still on 1/2 strength Power-Gro nutes as well. They seem to drink about 5 litres of water every 3 days.

HydroSan

Hi weedmonster,

I can't say I've ever experianced this, but I'd flush anyway and bang in some fresh nutes. if you can't bring it up, fresh nutes should do it

San

weedmonster

i have brought it up, as i say its on about 5.2 now, will be on six by the end of day.

just thought it was wierd. unless i messed it up last time i done it.

but plants are all doing fine so no worrys

dowts

Do you let your water stand overnight before usingit, I was using the same unit i was just using tap water, but now i put about 6 ltr of water in a bucket let it stand overnight use this next top up then refill bucket ready for next top up. It still comes down but not as much my theory is your adjusting tap water once the florides settle this alters ph (only a guess)

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OzGrowa

I would dump the tank and start again, there is slight PH burn on the tips of those leaves, plants will use lots of anions out of a low PH solution and sometimes the plant will take too much nutrient with that especially if the initial EC or nutrient strength is too low. Many factors cause PH drop, often it can be the cycles of the plant or simply running a vey low solution like you are can cause instability, the plants look healthy though and its not a major incident.

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