Alkalinity Rising without dosing?

zwandz · Sep 6, 2022

I’m quite confused in my research of this.

My alkalinity has been rising with water changes from 9.3 to 10.2 - weekly 20% water changes using IO salt

But I can’t put a finger on why.

Calcium was at 390 week 1, and 440 week 2. It’s stabilized at 430 for the past two weeks.

Nitrates stay less than 5

salinity 1.025 and temp 78

RODI water - the past week I began making my own, switching away from LFS bough but it’s been a steady rise so doubtful this is the reason

I think I’m going to start being more precise with changes - testing the new salt and adjusting it as needed but… tips on this? And insight on the rising alk?

vaguelyreeflike · Sep 7, 2022

What salt are you using? Have you tested the new salt water before it goes in the tank?

Reef. · Sep 7, 2022

IO salt is 11+ alkilinity, so your alk will likely raise with water changes, if your corals are not using much alk.

zwandz · Sep 7, 2022

vaguelyreeflike said:
What salt are you using? Have you tested the new salt water before it goes in the tank?

Regular IO. And no - starting immediately, especially as someone below pointed out their alk is really high in that salt

zwandz · Sep 7, 2022

Reef. said:
IO salt is 11+ alkilinity, so your alk will likely raise with water changes, if your corals are not using much alk.

How would I lower it when making new salt water?

christwendt · Sep 7, 2022

zwandz said:
How would I lower it when making new salt water?

You have to change salts to a salt that has lower alk. Try and use a salt that is what you keep your tank at.

fishface NJ · Sep 7, 2022

zwandz said:
How would I lower it when making new salt water?

Sodium Bisultate

Sodium Bisulfate to Reduce Alkalinity in New Salt Water or in Display Tanks

I just want to record these calculations in their own thread to refer back to in other threads. When alkalinity is too high in new salt water or in a display tank, acid can be used to lower the alkalinity. You can easily use muriatic acid (hydrochloric acid), or sodium bifulfate (e.g...

www.reef2reef.com

zwandz · Sep 7, 2022

christwendt said:
You have to change salts to a salt that has lower alk. Try and use a salt that is what you keep your tank at.

Thoughts on the sodium bisfulate article posted below?

zwandz · Sep 7, 2022

fishface NJ said:
Sodium Bisultate

Sodium Bisulfate to Reduce Alkalinity in New Salt Water or in Display Tanks

I just want to record these calculations in their own thread to refer back to in other threads. When alkalinity is too high in new salt water or in a display tank, acid can be used to lower the alkalinity. You can easily use muriatic acid (hydrochloric acid), or sodium bifulfate (e.g...

www.reef2reef.com

So doing this on a new batch of saltwater, the biggest thing is making sure it’s aerated enough to keep PH normal? Just a quick morning read so partially thinking out loud. Thank you!

fishface NJ · Sep 7, 2022

Yes mixing in a new batch of saltwater. When I mix my new batch I use a powerhear or pump to mix the IO well....usually for 24 hour before I would use it. My SPS tank does well when my dkh is around 7- 7.5.

Why do I continue to use IO if I need a lower dKh? I have many buckets sitting in a closet, and it not a big deal to add the sodium bisulfate

zwandz · Sep 7, 2022

fishface NJ said:
Yes mixing in a new batch of saltwater. When I mix my new batch I use a powerhear or pump to mix the IO well....usually for 24 hour before I would use it. My SPS tank does well when my dkh is around 7- 7.5.

Why do I continue to use IO if I need a lower dKh? I have many buckets sitting in a closet, and it not a big deal to add the sodium bisulfate

My most convenient LFS really only carries IO so I get that sentiment lol.

My 4 week rise hasn’t shown any change in my softies, but they’ve grown really well around the 9 range so that was my goal to keep that stable there. Do you think my new SPS would be good at 9? Everything I read preaches stability above all, but still

Randy Holmes-Farley · Sep 7, 2022

Your alk is fine, but if you want it lower in your new salt water, the sodium bisulfate is a fine way to do it. Muriatic acid is another, but is a bit harder to handle properly.

Reef. · Sep 7, 2022

zwandz said:
How would I lower it when making new salt water?

I use Seachem acid buffer, you need to mix the salt for 24 hours or use a air pump as lowing the alk also lowers the ph which is not good, you want to give time for your ph to come back up before adding the salt water to the tank.

If you want your display tank to have lower alk, either change your salt to one with lower alk or lower your salt mix, whichever method you choose.

zwandz · Sep 7, 2022

Reef. said:
I use Seachem acid buffer, you need to mix the salt for 24 hours or use a air pump as lowing the alk also lowers the ph which is not good, you want to give time for your ph to come back up before adding the salt water to the tank.

If you want your display tank to have lower alk, either change your salt to one with lower alk or lower your salt mix, whichever method you choose.

I'm going to lower at the salt mix level. While my alk may be in range right now, I don't want it to keep rising and it still seems high to me as is, when everything has been so happy at lower levels.

I ordered sodium bisfulate based on the post above - what's the difference between that and Seachem acid buffer, if any?

Reef. · Sep 7, 2022

zwandz said:
I'm going to lower at the salt mix level. While my alk may be in range right now, I don't want it to keep rising and it still seems high to me as is, when everything has been so happy at lower levels.

I ordered sodium bisfulate based on the post above - what's the difference between that and Seachem acid buffer, if any?

#RandyHolmes is the best man to answer this but I believe they are the same thing, so with your product you will likewise need to mix well and wait for the ph to lvl back up, an air pump greatly helps with this.