Carbonate Hardness Dropping

[sen5241b]

Did a 5G change out 24 hours ago and the alk and Ph came up a little, I think there is about 20-25 gallons of water in my tank.

Latest test


Temp 78
Salinity 1.026
Ph 8.0 (was 7.8)
Alk 6dkh (was 5 dkh)
Calcium 450
Mag 1700+ (yes, I re-tested it very carfully a second time with the Red Sea test)

What's with this mag? Problem? Related to low alk? Damn, maybe we need to be chemists to understand this case!

 

[ccCapt]

What salt did/do you use? If Oceanic, that mag is about right. Typical for Oceanic..totally unbalanced with very high ca, low alk and very high mag.

 

[sen5241b]

Yes, Oceanic. That the alk and Ph came up after a water change tells me I need to do more changes. Also, the mag was not that high in the past.

 

[tankedchemist]

watch out with drastic pH changes-- it will really stress out your fish! Remeber, it's a logarithmic scale... so even small changes in pH result in a huge change in the chemistry of your water. I believe people usually suggest no more than 0.2 change in pH daily.

Did you measure the pH at the same time of day both times? that can affect the readings, as well.

for the mag problem, try rolling the bucket of salt around to mix thoroughly before you measure it. or if you have the bag stuff, shake it up.

 

[yote]

+1 Tanked.

 

[sen5241b]

watch out with drastic pH changes-- it will really stress out your fish! Remeber, it's a logarithmic scale... so even small changes in pH result in a huge change in the chemistry of your water. I believe people usually suggest no more than 0.2 change in pH daily.

Did you measure the pH at the same time of day both times? that can affect the readings, as well.

for the mag problem, try rolling the bucket of salt around to mix thoroughly before you measure it. or if you have the bag stuff, shake it up.

Interesting. For that last water change I used the salt at the bottom of a big jug. I always shake the salt jug upside down. Will big Ph swings stress the corals too?

 

[yote]

Big swings in PH will stress everything in the tank.

 

[sen5241b]

I've been doing a series of smaller water changes and the Ph has been rising back up towards normal. Its now above 8. I'm concluding that regular water changes help keep Ph and Alk stable.

 

[ccCapt]

I'm concluding that regular water changes help keep Ph and Alk stable.

:Cheers:

 

[daugherty]

+ 1 ccapt

 

[sen5241b]

What about these advanced marine aquarists who never do water changes? I figure they must be dosing to maintain stable Alk. No?

 

[daugherty]

yes most dose every day. i do water changes and i still have to dose the keep my levels were i want them.