pH corrected, now really high alkalinity

[somebloke]

My first marine tank just finished a fishless cycle. Ammonia 0, Nitrite 0, Nitrate 25. I noticed the pH was a bit lower than I wanted, around 7.7. At the same time, alkalinity measured at about 150 ppm. I did a little research and added baking soda to get my pH up to 8.1. That was within the past 24 hours. Just tested my alkalinity and it is above the Hanna tester Max of 300 ppm. I tested it twice just to be sure.

The only other thing I did in the past 24 hours was gently add an additional (rinsed) small bag of aragonite sand raising the volume of aragonite sand by 25%.

What the heck happened? Why did my alkalinity skyrocket? Any insight much appreciated. I'm usually fairly good with prep and research so this is really annoying me.

 

[saltyfilmfolks]

My first marine tank just finished a fishless cycle. Ammonia 0, Nitrite 0, Nitrate 25. I noticed the pH was a bit lower than I wanted, around 7.7. At the same time, alkalinity measured at about 150 ppm. I did a little research and added baking soda to get my pH up to 8.1. That was within the past 24 hours. Just tested my alkalinity and it is above the Hanna tester Max of 300 ppm. I tested it twice just to be sure.

The only other thing I did in the past 24 hours was gently add an additional (rinsed) small bag of aragonite sand raising the volume of aragonite sand by 25%.

What the heck happened? Why did my alkalinity skyrocket? Any insight much appreciated. I'm usually fairly good with prep and research so this is really annoying me.

Was it dry sand?

 

[somebloke]

Was it dry sand?

Yes, Caribsea aragonite, dry

 

[saltyfilmfolks]

And don't sweat the ph. There nothing in the tank yet to effect it as far as co2 uptake and little to expel co2 as well. Just the bacteria.

 

[mtraylor]

what kind of alkalinity test kits measures in ppm?

 

[somebloke]

And don't sweat the ph. There nothing in the tank yet to effect it as far as co2 uptake and little to expel co2 as well. Just the bacteria.

Okay, do I sweat the alkalinity?

 

[saltyfilmfolks]

Yes, Caribsea aragonite, dry

It's reacting to the salt water and releasing carbonate.

Keeping in mind it's not sand or rock it's crushed coral Skeleton.

 

[saltyfilmfolks]

Okay, do I sweat the alkalinity?

No. If the tank is empty don't sweat nuthin.

 

[somebloke]

what kind of alkalinity test kits measures in ppm?

Hanna Checker Marine. Has a colorimeter with a digital display

 

[saltyfilmfolks]

Def look under the chemistry forum at Randy Farley articles. Some great stuff there.
Look at the beginner and basics.

And def keep asking questions!

 

[somebloke]

It's reacting to the salt water and releasing carbonate.

Keeping in mind it's not sand or rock it's crushed coral Skeleton.

Understood, and I imagine there was some fine "dust" despite rinsing it. So, basically just wait for the alkalinity to come down before adding stock?

 

[somebloke]

Def look under the chemistry forum at Randy Farley articles. Some great stuff there.
Look at the beginner and basics.

And def keep asking questions!

Will do, thanks!!!

 

[mtraylor]

just found the hanna kit.
1ppm caCo3 = 0.056 dkH. So 300 would be dkh 16.8. You need a do a water change.
The 150ppm would have been 8.4dkh. You were good there.

 

[saltyfilmfolks]

Understood, and I imagine there was some fine "dust" despite rinsing it. So, basically just wait for the alkalinity to come down before adding stock?

Yes. It may take some some time as it has to cure and cycle. Once the outer layers are coated in bacteria the reaction slows down.
Even though many many say it's fine it's not.

Oh fwiw. In a reef you'll not want to buffer the ph really. Alk and cal are related. Alk increases ph. But you can get lopsided in their balance. Kalk is a better soloution but you far from there right now.
Good airation and gas exchange to rid the tank of co2 is much better currently. So don't be surprised if it stays low ish for a while.

 

[saltyfilmfolks]

just found the hanna kit.
1ppm caCo3 = 0.056 dkH. So 300 would be dkh 16.8. You need a do a water change.
The 150ppm would have been 8.4dkh. You were good there.

The aragonite is buffering the heck out of the water right now. It'll just keep happening. Gonna take some time.

The biomagnet stuff in live sand would be a better soloution to coat the rock sooner.

 

[mtraylor]

Yeah it may be best to ride it out for a while.

 

[saltyfilmfolks]

Yeah it may be best to ride it out for a while.

yea I found out the hard way. Actually was repeatedly told it was ok by reefers, found the info on a freshwater site.

 

[Orly20]

@somebloke im having he same problem with my tank having high alkalinity with me dosing any. I also have the same substrate, Carib Sea Argonite and it's been in the tank now for about a year. I have no idea how to keep the alk low

 

[ajm83]

How much baking soda did you add in total?

 

[saltyhog]

Soda ash (baking soda cooked) is the alkalinity additive in most 2 part dosing schemes. You just added a huge amount of alkalinity additive to your tank....hence the rise in alkalinity. The effect of adding alkalinity on your pH is very short lived. If you keep adding it the pH will keep going down and you end up where you are.....very high alkalinity and eventually the same pH.

Don't chase pH or use additives to get it to a certain number. Make sure you have adequate air exchange and don't fret it.