RO Water + Crystal Sea Salt = HI PH !?!?

[bheron]

Ok, I've been trying to solve my High PH problem for awhile now. here's where I am - ANY HELP WOULD BE SOOOO APPRECIATED!!!
I buy my RO water from Walmart: 1 Gallon Jugs "Great Value Sodium Free Drinking Water". It says Reverse Osmosis right on this side. I test this water and it gives a PH reading of about 6.5.
Then, I add Crystal Sea Marine Salt to the water, let it dissolve for 10 mins or so, and get a PH reading the the neighborhood of 8.8!!
Any clues as to why this is happening? I thought previously my Sea Salt must've been bad, but I just bought a whole new bucket. So I'm assuming it just doesn't react well with the particular RO water from Walmart (I just assumed RO water was RO water just the same).
Any ideas?

 

[birdy]

You should let your salt dissolve for several hours, preferably overnight and the temp should be around 75 or higher, then test and see where it is at. I am not sure if it will make a difference but 10 min isn't long enough to get an accurate reading.

 

[ophiura]

I agree, let it sit and mix (if possible get a powerhead) overnight and then test it. The pH can go very screwy short term like that.
HOWEVER, I have heard of people having this trouble with certain brands of salt or certain batches of salt. It is possible. But I am not familiar with that brand in particular.
Definitely give it over 12 hours and see what happens (and, as noted, also get the temp up)

 

[bheron]

Thanks.
I actually do this - aerate with power heads and raise temp to 79 for 24 hours and still received the reading.
Ophuira - you're the first person that's mentioned you heard of this before. This brand is what's carried at my LSF and they say its the best around. Any leads??

 

[madd catt]

You could try changing the salt or ro/di brand too see if it is 1 or the other.

 

[broomer5]

bheron
I'm not familiar with that brand of synthetic sea salt either.
Not sure why it's mixing to pH 8.8 ~ but it doesn't sound very good.
It could be the saltmix.
It could be the ph test kit.
It could be both.
What test kit are you using ?

 

[bheron]

I am using a Dry Tab test kit.
Yea, guess I should try alternating both - that would give me a more accurate read.