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COCO COIR RO water & ph problems

Once you add the fertilizer to the RO water it is no longer RO water, because you have added salts back in. Reverse Osmosis removes most minerals. Distilled water removes all minerals. The EC of your RO water with fertilizer should be much higher then the EC of your plain tap water. I use Muriatic acid to bring ph down (only a few drops). I read somewhere that PH down with MA provides a more stable ph...it will not drift, but in any event I have used it for several years now with no issue..Forget all the BS about MA I just read several threads saying it harms plants. I suspect it would if one pored in on there plants. I will be flamed for this...
 
Sometimes my meters (Hannah) seem to bounce around with the results..I will rinse them again in distilled water and take a another reading, more times then not the results stabilize...I clean the ph and ec meter in distilled water after every use and with the ph meter I always use a few drops 4.01 reference solution on paper towel tucked in the meter cap for storage.
 
Sometimes my meters (Hannah) seem to bounce around with the results..I will rinse them again in distilled water and take a another reading, more times then not the results stabilize...I clean the ph and ec meter in distilled water after every use and with the ph meter I always use a few drops 4.01 reference solution on paper towel tucked in the meter cap for storage.

I took my ‘Hanna'. Ph meter out of long storage to use with my first grows. I found it to be very unstable due to grime build up on the probe. Although it seemed drastic, I soaked it for a little while in weak bleach solution, using a small sable haired brush to wipe it with. After a good rinse in distilled water I calibrated it with Ph 7 buffer solution.. It was a bit erratic & I found I had to recalibrate every other day.
I adopted a routine: Before use I rinse in distilled water. I remove a 50ml sample from the bulk nutrient feed into a 50ml beaker. I rinse the meter in the main nutrient solution and then dip into the 50ml beaker I find this stabilizes the meter immediately and you get an acurate read off.

Before I go further, you should previously buy and use probe storage solution, this will help maintain stability of your instrument. ~ when I have calibrated the meter with Ph 7 buffer I put this amount into a separate bottle (use as a pre-rinse). I use this to rinse my probe before going into fresh Ph 7 buffer, this saves contamination.. When finished after every use, rinse with distilled water, then rinse in your used Ph 7 buffer. I then dry off using filter paper (contaminant free) then use a ‘Giotto’ air puffer (Amazon) Pour some storage solution into your probe cap; the solution I purchased had a piece of sponge which you can cut a piece off and place in your cap. After placing your probe in the cap keep the meter upright so there is no spillage. When you need to check your calibration, dip the probe in distilled water dry it off with filter or air puffer then into your used Ph 7 buffer (pre-rinse) then into your fresh Ph 7 buffer – there will be no cross contamination. I find my meter is completely stable and no need to calibrate for long periods

It is not recommended to store the probe in distilled water or Ph 4 - if no other choice, use Ph 7 only. The paper towel you tuck in the cap would most likely contaminate your probe, hence the eratic readings you get.

The above may be a bit ‘long winded’ :ouch: but it works for me. I found previously it was taking longer than necessary to get an acurate reading J


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I agree with your order of procedures. Though I only use distilled for calibrating time. Rinse is usually my well water.

So what's the best method for the 'slurry test' when testing soil pH?

Dig and get a sample and then 50/50 volumewise with distilled water?
 
Hi 3Berries, I was going to check on my air-pot coco/perlite in the next day or two. 50/50 or twice as much soil/coco as distiled water.
seems usual -most just stir it around for a few minutes. A more accurate method would be to give it a good mix ~ leave it for an hour or more if convenient, filter through a gauze and then test the liquid. I have found measuring amounts in a 50ml beaker give more stable readings.
 
Thanks Heisenbud. I measured my pH run off on the inside stuff for the first time today and both are doing great, around 6.8. I use some 'soluble' limestone in the soil mix. But one is FF Ocean Forest and the other is ProMix BX.

But was wondering about my outside raised beds.
 
Probably won't bother with my coco slurry Ph just yet; although I do like to fiddle :laugh: today feed in EC 1.4 Ph 5.9 ~ run off EC 1.1 Ph 6.17 so all seems well. Just wished I could have trained my plant 130 cms and running out of head room:ouch:
 
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From time to time I have to snip off a bit of the ph probe...Learned the hard way to use tweezers and be very careful...last time I had to replace the meter after a "O shit" moment.
 
I did a slurry test from my raised bed outdoor gardens. 100 grams of soil, 50 gram distilled water, mix well and let sit for 15 minutes then strain through a coffee filter. it came out at 6.8. I was quite pleased.

The soil has been in use for decades. I usually throw in some lawn starter fertilizer (high P) and limestone every year and turn it over once in the spring. Let clover grow as a weedy ground cover and soil builder. Last spring I added Calcium Nitrate too for the first time.
 
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