Help me understand Sap Ph Meters and Refractometers

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oxanaca

oxanaca

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so ive tried this before but kind of gave up as i had a hell of a time collecting enough plant juice.
is anyone aware of a good press for this purpose.
im thinking a devices that uses a piston pushed by a threaded screw would be the best way, is this available
 
Seamaiden

Seamaiden

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Ha! My problem as well, I have zero hand/arm strength. Thus, why I started using the petioles, if you use enough you can get a drop. A drop. Others have fiddled around with various plies with plates welded onto them, garlic presses (not worth it IMO). You know what I've been thinking might work best--a battery operated stick blender or some such, and then press for juice.
 
Herb Forester

Herb Forester

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Nutri-tech and Pike both sell custom vice-grips. I use a welder clamp and drip the sap off a corner. My friend has a strong metal garlic press and it works fine. You may need to fold or reposition a few times to get some good drops.

I bet a tiny hole drilled in the end of one of those hash puck presses could work well. I carry my test kit around to several gardens, so the hydraulic jack unit is too cumbersome for me.

If you want to know what's happening in the leaves, I think it's important to take sap from blades and not just the vascular parts which hold more water. We've also started sampling calyx material, but I don't yet have the K ion meter to make those assessments.
 
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Seamaiden

Seamaiden

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I've read poor reports on usability of those custom vice-grips, Herb. Again, what do people like myself with very poor hand & arm strength do in this situation? I wasn't able to do anything except make mush with the leaves. So I tried it with my squashes. Same thing, I made mush, but nary a single drop of sap to measure.

It did occur to me that you could titrate somehow, add water and then calculate, possibly, to come up with an accurate number. I'm just not sure how that would best be done.
 
J

Jalisco Kid

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My garlic press from bed bath and beyond works well. I use whole leaves. For me the objective is to use this as a guide. Going for real precise numbers is not necessary for me. I look at the values my best plants give me, then look for deviations.JK
I do this around lights on with my coffee. There is more moisture in the leaves at this time. I am using the same time so the numbers stay relevant.
 
Herb Forester

Herb Forester

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My garlic press from bed bath and beyond works well. I use whole leaves. For me the objective is to use this as a guide. Going for real precise numbers is not necessary for me. I look at the values my best plants give me, then look for deviations.JK
I do this around lights on with my coffee. There is more moisture in the leaves at this time. I am using the same time so the numbers stay relevant.
What values do your best plants show at lights on?
 
oxanaca

oxanaca

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My garlic press from bed bath and beyond works well. I use whole leaves. For me the objective is to use this as a guide. Going for real precise numbers is not necessary for me. I look at the values my best plants give me, then look for deviations.JK
I do this around lights on with my coffee. There is more moisture in the leaves at this time. I am using the same time so the numbers stay relevant.
i use a garlic press and i think i got it from BBB but i have to put quite a few leaves in it even to get one drop. the two pieces dont fit together real well, its an oxo so i thought it would be quality.

im going to try again tomorrow. interested to hear your numbers.
 
oxanaca

oxanaca

322
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Nutri-tech and Pike both sell custom vice-grips. I use a welder clamp and drip the sap off a corner. My friend has a strong metal garlic press and it works fine. You may need to fold or reposition a few times to get some good drops.

I bet a tiny hole drilled in the end of one of those hash puck presses could work well. I carry my test kit around to several gardens, so the hydraulic jack unit is too cumbersome for me.

If you want to know what's happening in the leaves, I think it's important to take sap from blades and not just the vascular parts which hold more water. We've also started sampling calyx material, but I don't yet have the K ion meter to make those assessments.

hey thanks for steering me in the right direction. im going to try this, thanks ICFAGS
only $15 and you dont have to drill a hole the plates already have holes
http://www.amazon.com/Makins-Professional-Ultimate-Clay-Extruder/dp/B0018BOXWQ
 
Redux

Redux

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I believe that clay extruder is aluminum so wouldn't recommend for hash pucking. May be perfect for juice extraction for testing though.
 
Redux

Redux

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excellent they make a SS304 model but its $52
Thought they had a stainless steel model. It's been awhile. The SS model will hold up to the stresses better over time. I looked at them when I was attempting to find an inexpensive alternative to the Jack Puck presses.
 
Seamaiden

Seamaiden

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Excellent! Ordered to be sent to my local Wally World. Thanks so much, @oxanaca :)
 
oxanaca

oxanaca

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Excellent! Ordered to be sent to my local Wally World. Thanks so much, @oxanaca :)

get your press yet? mines gonna arive monday.
if you have what kind of brix did you measure, did it work for you?
 
Seamaiden

Seamaiden

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Oh man... I hope it's still there. I had a couple of emergencies this week and I completely forgot that I ordered the thing.
Facepalm
Good Christ. I knew I was forgetting something.
 
B

Bangarang

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Going to make this investment. So the most useful and general Sap meter is the Sap PH meter? Right??? What company should i order from?
 
oxanaca

oxanaca

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i ended up getting the stainless press yeasterday had a lot of problems but it got here.
its excellent. im able to get enough plant juice to cover the lense of the refractometer from a single medium sized leaf.

there is a trick to getting it to work though. i add the leaf to the inside of the cylinder and screw on the endplate with a bunch of small holes. i then turn the screw down until i see both juice and plant matter coming out of the holes. i unscrew the endplate then dump the stuff that squeezed out of the holes back into the press and press it again. the second time i squeze it i just get juice.

i seem to get between 5-7%brix from medium sized leaves near the top of my flowering mj plants this was taken in the last few minutes of lights on.

i also recorded 1%brix from a pathos vine. and 2%brix from my mother in laws tongue plant.
 
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