Ph dropping ridiculously low?

For as back as I can remember I've rarely needed ph up, I'm on a 2nd bottle of pH down and still have 3/4 of my 1st bottle of pH up.
With my last crop I noticed the ph was dropping just sitting in the reservoir, it's stable up until its nearly empty say 4/8 litres left then it drops like a stone.

I measured the last of it today (5tlr) and was 4.4 yesterday it was 5.9 and through the duration of the week 6.1/6.2?

It's not a problem because I know it's happening it's the why it's happening I'm curious about, ph rising is all I've ever seen and read about for the most part.

Sounds normal. That last bit left over in the rez can get pretty concentrated. You should refill sooner or lower EC some.

l only use ph down, baking soda if l overshoot, softens it up.

70's natureboy said:

Sounds normal. That last bit left over in the rez can get pretty concentrated. You should refill sooner or lower EC some.

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Good idea, I use ionic for vegging and its easy enough to do as you suggested, but I use canna for flowering and I don't want to mix ab into other mixed ab nutrient incase of issues, your meant to mix A 1st blah blah and i know zero about chemistry so I don't want to risk it.

Star Dog said:

Good idea, I use ionic for vegging and its easy enough to do as you suggested, but I use canna for flowering and I don't want to mix ab into other mixed ab nutrient incase of issues, your meant to mix A 1st blah blah and know zero about chemistry so I don't want to risk it.

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Find a one part mix, that way res stays clean, Cyco commercial is pretty good. Expensive but good.

I made this up to work out how much is getting used and to work out the run off, I can re ph and feed from that for now.
I might get away putting the last into a bucket then adding it back to new mix, normally my ph is 6.2 without any alterations, I'll try it and see.

Southernontariogrower said:

Find a one part mix, that way res stays clean, Cyco commercial is pretty good. Expensive but good.

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I meant to add its a 1 part, easy, simple and quick suits me great lol.

1 part do work out very expensive compared to a+b, to hit 1.2ec with ionic I need 6/7 ml per litre with canna it's 1.2ml, that's a huge difference!
I don't why it is 1 part is so expensive?

Star Dog said:

1 part do work very expensive compared to a+b, to hit 1.2ec with ionic I need 6/7 ml per litre with canna it's 1.2ml, that's a huge difference!
I don't why it is 1 part is so expensive?

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Paying for ease of use!

Southernontariogrower said:

Paying for ease of use!

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It is worth it lol, my clone tent isn't automatic so I've got to feed them daily, I go through phases of can't be bothered then I have some enthusiastic periods when loads of stuff gets done and enjoy them, I'm currently in a enthusiastic phase lol

Star Dog said:

Good idea, I use ionic for vegging and its easy enough to do as you suggested, but I use canna for flowering and I don't want to mix ab into other mixed ab nutrient incase of issues, your meant to mix A 1st blah blah and i know zero about chemistry so I don't want to risk it.

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You can mix the A B separately in a Home Depot Pail or something and top up the res from that pail. .

Star Dog said:

It is worth it lol, my clone tent isn't automatic so I've got to feed them daily, I go through phases of can't be bothered then I have some enthusiastic periods when loads of stuff gets done and enjoy them, I'm currently in a enthusiastic phase lol

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I use at 40% recomended dose, then add other things from there.