PH probe storage solution.

[gbroadbridge]

I've been using a DIY storage solution after cleaning my pH probe with Hanna pH probe cleaning solution, as Hanna state to soak in cleaning solution for an hour to recharge the electrode.

My DIY is a 3M solution of KCl which I mix 50/50 with a Hanna ph4 buffer.

Recently I read that perhaps a better solution is to take 100ml of ph4 buffer and dissolve 10g of KCl into it.

Does it really matter, and if so which would be better for probe longevity?

 

[blaxsun]

I've just been using the Hanna pH storage solution - you don't seem to need very much,

 

[reaper93]

Wait how often do you need to clean these?

 

[Randy Holmes-Farley Verified Community Expert]

Storage solution doesn’t matter a whole lot. Diluted seawater is also good. You do not want tap or RO/di because the low ionic strength will draw salts out of the probe.

KCl solutions are certainly good if you have it.

 

[gbroadbridge]

Thanks, as I have about 500g of KCl which I use to top off Potassium when necessary, I'll probably just use a 3M solution in future as a storage solution.

I'm not sure why most sites say to dissolve in pH4 buffer other than to ease the dissolution process. It takes a while to dissolve in RODI water

 

[gbroadbridge]

I've just been using the Hanna pH storage solution - you don't seem to need very much,

Out of stock forever it seems

 

[Malcontent]

For years I used a DIY storage solution made out of KCl and it made my probes less accurate and slow to stabilize. It got better when I purchased a proper storage solution but only for my newest probe. No idea what went wrong.

 

[gbroadbridge]

For years I used a DIY storage solution made out of KCl and it made my probes less accurate and slow to stabilize. It got better when I purchased a proper storage solution but only for my newest probe. No idea what went wrong.

Perhaps the new probe is the reason. I'm not sure why storage solution chemistry seems to be such a closely guarded secret.

 

[Malcontent]

Perhaps the new probe is the reason. I'm not sure why storage solution chemistry seems to be such a closely guarded secret.

The new probe quickly developed problems so I began to suspect it wasn't just that the old ones were left unused on the shelf for so long before being put to use.

Switching to a commercial storage solution restored the performance of the new probe but not the old ones though they did improve somewhat.

 

[gbroadbridge]

Here is one answer.

Storing a pH electrode: The Correct Way

www.westlab.com

I use a 3M solution as I can never get a 4M solution to completely dissolve unless I add pH 4 buffer.

 

[killer2001]

I keep a secondary pH probe mounted via magnet in the back of my AIO sump. Since I have an ATO, my water level is always true, so I mounted it in a way where the probe is always submerged.