High Ph Sand?

[princessearrings]

Hi! So I just found out that the sand I have been using in my 75 gallon is drastically raising the ph. Here is my reasoning for this:
I removed some of the sand and rinsed it with my well water (ph: 7.3), then I filled the container with R/O water (neutral ph), and let it sit for a day. Not much happened in that time period, so I thought that it might not be the sand. However, I just checked it today (a week later), and the ph is 8.0! If there could possibly be another reason for the ph to go up, please tell me.
My tanks ph is currently at 8.2. Is it the sand, or did I do something wrong when I tested the sand?
The sand is pool filter sand by the way, and on the bag that it came in it said it was just pure silica... now I'm not so sure.
Thank you!

 

[CK123]

Let what ever water you are filling your tank with sit over night or until all the bubbles are out of it and re-check PH.

 

[gomezladdams]

It shouldnt be aragonite if the bag says silica but who knows.You can test a sample of the sand with some muriatic acid(be careful it can burn you) from the hardware store.If it bubbles its aragonite and will affect your PH.In which case post where you got it and all the rift lake cichlid keepers in your area will decend on the place like locusts lol.

 

[boldtogether]

The only sand that I know of that will do that is ^^what he said, arragonite^^ or maybe crushed coral.
Murriatic acid test it and if it reacts...buy new sand? I dont know what else you could do to test sand.
Have you added any decor lately, like sandstone, or limestone or some such? even a small piece can alter a ph test.

 

[turboGarrett]

I had the same thing happen with some sand labeled as "pure silica".