pH has dropped suddenly...

[Crabby]

Hey all,

I measured the tank parameters yesterday for my 29 gal community, and I was shocked when my pH read around 6.2. I don’t use a buffering substrate, and don’t use RO or rainwater, just dechlorinated tap. I can’t see why it might have dropped so quickly. For reference, it usually measures 6.6-6.8, so it’s a decent drop. My tap is neutral. Any ideas on why this would happen? 
Also, will salty shrimp bring the ph up a bit? I will dose a little bit anyway, but I’m hoping it’ll help the ph.

Thanks in advance folks!

Crabby

Edited December 22, 2019 by Crabby

[Crabby]

To follow up, today I did a 45% water change, and dosed about 6 g of salty shrimp, and now the params are back to normal. pH 6.8, GH 4 and KH 2. I underestimated the effect of salty shrimp (won’t do that again), and may have slightly shocked the inhabitants, but they all seem fine.

[jayc]

The natural process of the beneficial bacteria breaking down Ammonia into Nitrites and then Nitrates increases Hydrogen, which in turn influences the pH level of a tank. Ammonia is a compound of nitrogen and hydrogen with the formula NH3. So when Beneficial Bacteria "eats" up the Nitrogen (N), what are you left with? 3 molecules of Hydrogen (H3). And the more Hydrogen you have in the water, the lower your pH. 

If you are lax in water changes, ph will drop due to this cycling process where Nitrogen is constantly being removed.

Tap water is also high in pH, as it contains chemicals and minerals that are designed to keep pH high (alkaline pH avoids corrosion of pipes and teeth). 

 

Only Salty Shrimp GH/KH+ will raise pH.

Salty Shrimp GH+ does not increase pH.

Which one do you have?

 

So if you used tap water and SS GH/KH+ for your water change it would increase pH a lot more than just using one or the other.

[Crabby]

Thanks for the chemistry lesson jayc! Really, really helpful and interesting. I thought the problem might be started from high ammonia, because I added 4 new fish to the tank this week. I use SS Gh/KH+.

[jayc]

36 minutes ago, Crabby said:

I use SS Gh/KH+.

So the combo of tap water and SS GH/KH+ will help maintain a stable pH for your tank. But you need to be regular with the water changes. Nature is not stopping with the Nitrogen cycle, so neither can you.

 

39 minutes ago, Crabby said:

I thought the problem might be started from high ammonia

It's probably one of the causes. The added ammonia load from more fish, caused more ammonia. More ammonia was broken down by the beneficial bacteria, leaving more ... Hydrogen! And remember, more Hydrogen means lower pH. 

 

In very mature tanks, it's sometimes a good idea to add a buffer. Like shell grit. The lower the pH gets (acidic) the more carbonates are released from the shell grit thus buffering the pH higher. I would only recommend this for very mature filters/tanks.

[Crabby]

1 hour ago, jayc said:

In very mature tanks, it's sometimes a good idea to add a buffer. Like shell grit. The lower the pH gets (acidic) the more carbonates are released from the shell grit thus buffering the pH higher. I would only recommend this for very mature filters/tanks.

It's not that mature yet, about to hit 6 months.

 

1 hour ago, jayc said:

But you need to be regular with the water changes.

Yeah, umm, I didn't do any for a little while about a month ago, but the last 3 weeks I've been doing a 50% every week before this happened. So not too sure if that correlates.

Edited December 23, 2019 by Crabby

[jayc]

9 minutes ago, Crabby said:

Yeah, umm, I didn't do any for a little while about a month ago

That would be the reason why you noticed a sudden drop in pH.