Wood Increasing Ph?

[Sillyjady]

Hello,
I'm new to this page so here is info about my setup:
-10g
-2 sponge filters (have not been changed in quite some time, I'm mostly using them for oxygen)
-Full spectrum led light bar
-Carbon filter padding cut to fit one end of tank for java moss to creep on
-flourite clay gravel
-live plants: windelov java, java moss, 2 dwarf anubias, 3 crypts
-12 chillI rasboras
-shrimp: 3 bloody mary, 2 blue, 1 Crystal
-I use flourish about 1 time weekly for plants
-I have pest snails and 2 assassin's placed in there recently
-I use Portland city tap water (pH 7, ammonia .225) and prime dechlorinator/ammonia neutralizer

I know it's kind of a wonky setup but it started out as a planted tank test and grew from there. Anyways...

Micro rasboras love lower pH and it tends to really bring out their color. I work at a pet store and we are always preaching about how wood (tannins) lower pH, and coral/shells tend to higher it. So having a pH naturally in my tap of 7.0 I decided to try wood to lower it.
First I added a large (tapered but 12" long) mopanI piece. Some tannins came out. I tested, and my pH had dropped to 6.8 (mind that this was with test strips but it seemed to be going the right direction). Then I did a water change, waited a few more days and tested again. 7.6 oh. Tap still tests at 7.0 and I have never had this high of a pH before. I got a master kit to be certain and it's still high.
So I bought a different drift wood piece
That's about the same size. Again, tannins released, pH dropped to 6.6ish with the master kit and I was fairly happy with the result. 2 water changes and a few days wait later... pH is back at 7.6

I'm stumped, any thoughts?

I know it won't kill my fish/plants/shrimp at this point. But the coloration is poor due to the stress and I just really want to learn more and understand what is happening.

Thanks!

 

[mattgirl]

Welcome to fishlore.

The higher PH may not be coming from your driftwood.

Try this: draw a glass of tap water and let it set for at least 24 hours and then run your PH test on that water. I don't understand the chemistry behind it but I have seen this happen before and when the test was done the way I suggested, tap water straight from the tap has a lower PH than water that has had a bit of time to age. HTH

 

[SegiDream]

I suspect it's the flourite substrate. I've heard these "plant friendly" substrates can affect ph (some raise or lower it). So a quick google search says Flourite Black Sand gives off high amounts of sodium and calcium. Which could raise your kh and thus your ph, I think maybe?

 

[NavyChief20]

Welcome to fishlore.

The higher PH may not be coming from your driftwood.

Try this: draw a glass of tap water and let it set for at least 24 hours and then run your PH test on that water. I don't understand the chemistry behind it but I have seen this happen before and when the test was done the way I suggested, tap water straight from the tap has a lower PH than water that has had a bit of time to age. HTH

So the science behind pH change in water that sits has to do with gasses coming out of solution. This happens faster in heated water for obvious reasons. As for the driftwood it will drop pH but not significantly.

As far as the substrate Flourite is inert. it will just absorb minerals for the plants it will not alter pH.

 

[Sillyjady]

Welcome to fishlore.

The higher PH may not be coming from your driftwood.

Try this: draw a glass of tap water and let it set for at least 24 hours and then run your PH test on that water. I don't understand the chemistry behind it but I have seen this happen before and when the test was done the way I suggested, tap water straight from the tap has a lower PH than water that has had a bit of time to age. HTH

I will give this a try, thank you.

Thank you for the knowledge!

 

[mattgirl]

I will give this a try, thank you.

Thank you for the knowledge!

You are very welcome. We are all here to learn more so we can take better care of our water pets. It seems I learn something every time I come here. Thank you NavyChief20 for explaining the why.

 

[NavyChief20]

You are very welcome. We are all here to learn more so we can take better care of our water pets. It seems I learn something every time I come here. Thank you NavyChief20 for explaining the why.

You're welcome ma'am

 

[SegiDream]

So the science behind pH change in water that sits has to do with gasses coming out of solution. This happens faster in heated water for obvious reasons. As for the driftwood it will drop pH but not significantly.

As far as the substrate Flourite is inert. it will just absorb minerals for the plants it will not alter pH.

Well my bad. The first few results I had indicated otherwise. But seachem website says it doesn't affect ph so guess that rules that out. Sorry OP, but I'm sure the others can help you figure it out.