Why would PH soar during a cycle?

[gregcuoz]

I just reached the first hurdle after 4 days as my inital ammonia deposit finally went down to between 1-2. I spiked it back up to 4. I tested ammonia today and its at 4. Tested Nitrites and its between .25 and .50 (AWESOME!!!). I was thrilled when I saw Nitrites! My smiles turned into after I tested the PH. The High Range PH went from between 7.4 and 7.6ish to 8.2-8.4. I have sand (play sand) substrate.
TIA

 

[gregcuoz]

Darnit (id say another word but the filter wont allow it). I was just informed (thx Jess) that play sand is the issue. I did a search before buying my sand and I saw Play Sand and Pool filter sand as the 2 biggest suggestions and saw no cons to either one. No pool store are open this time of year that I know of, so I went play sand.

So, heres the question.... How do I get 150lbs of play sand out, and add 150lbs of another sand with a tank full of water, without effecting my cycle?

 

[bs6749]

Whoever is telling you that play sand is effecting your pH has absolutely no clue. The reason that your pH has increased is because of your increasing ammonia levels. These are directly related. The more ammonia you have in the tank, the more the pH will increase (to an extent). The more you decrease the pH with a strong acid added to a tank that has ammonia in it, the less ammonia you will see (and the more ammonium ion you will see) after the tank has come to equilibrium. This is basic chemistry.

 

[jlk]

Playsand is generally a calcium-carbonate base. Yes, there are some that are made of a silica/quartz base or a mix of carbonate & silica/quartz but i have found these to be less common in home improvement stores for sand options. Calcium carbonate sand does increase Kh levels & directly affect ph. Its probably why its choosen for high ph/kh tanks such as for housing African cichlids.