Rocks lowering pH

[pairustwo]

I picked up these nice black pieces of rock that I thought about using for tank landscaping. They are the type that are completely flat on top and bottom sort of like shale, often used for retaining walls.

So I cleaned them up and put them in a 5gal bucket with tap water to see what they would do. They lowered the pH from 7.2 to about 6.9 after about a week.

I use Neutral Regulator on my tank to remove chlorine and chlormine and ammonia. It also adjusts the pH to 7. I was thinking about switching to Prime which I guess removes the bad stuff from tap water but doesn't adjust Ph.

So I wonder: should I avoid using these rocks?
If I keep using Neutral Regulator the rocks may gradually change the water from 7 (Neutralized Tap - where my tank stays right now) to 6.9. But the regulator would probably keep it steady at 7.

Or should I phase out the Neutral Regulator and phase in Prime, changing my tank from pH 7 to the tap waters 7.3 and forget about the rocks altogether?

Thanks for any advice.

Pairustwo

 

[SparKy697]

I'm familiar with rocks like limestone raising pH but this is a new one for me. Are you sure that the pH would not have changed over the same amount of time in an open bucket with no rocks in it?

I would stop using the pH regulator all together and let the tank be where it wants to be. 6.9 is nothing to be afraid of. Once you start messing with the pH, you are doomed to always adding chemicals to it.

 

[bs6749]

Are you using slate? It should, if anything, raise the pH level of the water as mentioned and not lower it.

 

[pairustwo]

I believe it is black slate.
So what variables am I missing? Would tap water sitting in a plastic bucket change pH for any reason on its own? The bucket was holding Flourite substrate for about a year but then it was used to fill up my tank - that was like rinsing it out ten or more times. It has been really cold outside where the bucket was.

The ph definitely went down.

I would stop using the pH regulator all together and let the tank be where it wants to be.

Well the tap is 7.2 sometimes it comes out a little higher. which I understand isn't bad. Should I just stop the conditioner and let the fish deal with the one time transition?

Thanks

 

[Fishyfanatic]

Stop using the regulator. Your pH out of the tap reads at 7.2. After 24 hours it naturally gases out and probably decreases to 6.9 on it's own. I've never heard of a rock causing a pH drop. Switch to the Prime.

 

[gu2high]

pH7.2 to pH6.9 after a week is not a problem at all. Don't bother with it.

I use a substrate Turface MPV which gives pH6.2 (my tap water is around 7.0) initially, I added a small bag of crushed coral in the filter and a big limestone in the tank to raise pH to 7.2. Then I removed the limestone and the pH has been stable around 7.0 for weeks. I guess the substrate affect pH more at the beginning but after several weeks it doesn't affect much anymore. Your stone may be similar.

 

[pairustwo]

After 24 hours it naturally gases out and probably decreases to 6.9 on it's own

Hold on there partner! Wouldn't that mean that my tank pH would go up when I do a PWC and then go back down to 6.9 as it gases out?

That seems like the sort of pH roller coaster that people warn about.

Am I thinking about this all wrong?

Pairustwo

 

[Fishyfanatic]

It is VERY common to have a different pH from the tap than you would have after sitting out 24 hours. Mine comes out around 7.0 from the tap but raises to 8.8 after sitting out for a day.

 

[pairustwo]

If you use a python like me doesn't that create a yo - yo effect on you tank's pH?