Only one aquarium has no buffer (KH)

[Jumbo Slim]

Hi

I moved to a new house.

Was on very hard well water with low buffer. High pH around 8.4

My new house has hard water with medium buffer out of the faucet. Moderate pH around 6.8 but it fluctuates.

Surprisingly all my neo-cardinia shrimp and live bearers adjusted pretty well.

Now I am about a week in and one of my shrimp tanks is seeing die offs. Plus the shrimp in that one tank aren't acting normal. Very slow and barely moving.

So I test the problem tank with Coop test strips:

300+ hardness
0 buffer
6.4 pH

Wow!

So I test the other 7. They all come out like this:

300+ hardness
80 buffer
6.7 pH

Any idea what could cause this in only one tank? All the water is from the same source.

[Fish Folk]

Can you describe your substrate, hardscape, plants, filtration, flow, temperature, stocking…

[Colu]

You could add some crushed coral to your filter to help increase your KH in the short term you could add some wonder shell 

[Jumbo Slim]

On 11/22/2022 at 8:21 PM, Colu said:

You could add some crushed coral to your filter to help increase your KH in the short term you could add some wonder shell 

Yes this part I realize. But I am wondering why one of 7 tanks would have such different numbers.

On 11/22/2022 at 7:31 PM, Fish Folk said:

Can you describe your substrate, hardscape, plants, filtration, flow, temperature, stocking…

Only neo-cardina shrimp, no fish.

Plain aquarium gravel, 1 pothos growing out the top, 1 sponge filter on an air pump. Same as the other 7 more or less.

There is a piece of wood in the tank. But there are also pieces in some of the other tanks. And this is not new wood. It was in the same tank at my old house for over a year.

 

[modified lung]

On 11/22/2022 at 5:40 PM, Jumbo Slim said:

But I am wondering why one of 7 tanks would have such different numbers.

There are a number of microorganisms and a few plants that eat carbonates and bicarbonates. That would be my guess.

[Jumbo Slim]

On 11/22/2022 at 9:03 PM, modified lung said:

There are a number of microorganisms and a few plants that eat carbonates and bicarbonates. That would be my guess.

Anyway to deal with those? Total rehaul of the tank, removing any substrate and hardscape?

[Jumbo Slim]

Thanks.

Added 1 pound of crushed coral and a wonder shell from the COOP.

That was November 25.

Today December 4, still getting exactly the same readings on test strip. Shrimp continue to die slowly.

All other tanks remain normal.

I would really love to figure this out.