Alk going up without dosing.

[rahger]

That is strange and I've never experienced this ever, but if you have absolutely no demand and your adding something containing alkalinity I could see this happening, but even a small amount of coraline algae should be enough of a demand to keep this rising alk stable. What does your tank look like ?

Depending on tank volume 7-14 days to go from 8.0-8.7 is not allot , and there are allowances for testing errors, so I'm still wondering if there is something unknown being added.

I'm no chemist , but randy dropped a little information here it would be great to ask him directly to see if maybe he could shine some light on the subject for you, and possibly have some quality information for you, if not he probably already has the information out there.

he said nitrate consumption releases alk. but that's kinda where the conversation about the most viable scenario ended.
if that's the case, what do i do about it?
lemme snap a pic really quick.

 

[rahger]

super quick nikon pic

 

[thatmanMIKEson]

super quick nikon pic

Yeah that back wall should handle a demand in 14 days, something has to be adding alkalinity, what is your daily additions?

Good looking set up!

 

[thatmanMIKEson]

Obviously check your test kit and verify it with a second brand and style of test. To be sure what your seeing is what is happening.

 

[rahger]

Yeah that back wall should handle a demand in 14 days, something has to be adding alkalinity, what is your daily additions?

Good looking set up!

0 dosing.
thanks, it was a long process deciding on the equipment and such but since then it's been a roller coaster.

Obviously check your test kit and verify it with a second brand and style of test. To be sure what your seeing is what is happening.

i got ATI ICP testing done on 2-20-23 and alk came back 0.02 higher than the trident and the ca/mag came back within margin of user error. my hanna alk tester always comes back 1.0 higher for somereason.

 

[rahger]

Normally it takes two weeks to increase 0.80 -1.0 but it did it in 6 days. If alk is being released during the reduction reaction how do I make it stop?

 

[Randy Holmes-Farley]

Normally it takes two weeks to increase 0.80 -1.0 but it did it in 6 days. If alk is being released during the reduction reaction how do I make it stop?

If you are dosing nitrate, you can switch to amino acids or ammonium chloride.

You can also do more regular water changes with a low alk mix. You can make new salt water as low as you want in alk, even negative if you desire, though that begins to have a substantial pH lowering effect as well.

Raising pH using low CO2 air in some fashion (outside air, a CO2 scrubber, etc) will increase alk demand.

Adding more alk consuming creatures will also lower alk.

Finally, you can VERY SLOWLY add alk reducing chemicals to the aquarium (sodium bisulfate or hydrochloric acid, for example).

 

[rahger]

If you are dosing nitrate, you can switch to amino acids or ammonium chloride.

You can also do more regular water changes with a low alk mix. You can make new salt water as low as you want in alk, even negative if you desire, though that begins to have a substantial pH lowering effect as well.

Raising pH using low CO2 air in some fashion (outside air, a CO2 scrubber, etc) will increase alk demand.

Adding more alk consuming creatures will also lower alk.

Finally, you can VERY SLOWLY add alk reducing chemicals to the aquarium (sodium bisulfate or hydrochloric acid, for example).

I haven’t dosed nitrates in forever. But I can start the AAs again.

My pH is usually 7.9-8.1 but maybe I can run the air stone line outside.

More water changes seems expensive. But do able. I’m not sure on the size and frequency needed to stop the swinging.

I’m hesitant about adding more alk consuming things cause even the corraline on the back wall looks thinner than it did a few weeks ago which makes me think that it’s just not stable enough for stony corals.

how slow is very slowly for hcl dosing? And where can I even get thst

 

[Randy Holmes-Farley]

I haven’t dosed nitrates in forever. But I can start the AAs again.

My pH is usually 7.9-8.1 but maybe I can run the air stone line outside.

More water changes seems expensive. But do able. I’m not sure on the size and frequency needed to stop the swinging.

I’m hesitant about adding more alk consuming things cause even the corraline on the back wall looks thinner than it did a few weeks ago which makes me think that it’s just not stable enough for stony corals.

how slow is very slowly for hcl dosing? And where can I even get thst

Starting amino acids wont necessarily cause an alk decline.

If the alk rise is 1 dKH per 6 days, that's 0.17 dKH per day.

A 10% water change once every 6 days with a mix that is 6 dKH below the tank will stop that rise. You would have to make such a mix with normal salt plus an alk lowering agent.

Or you can add the alk lowering agent directly to the aquarium (in a sump).

A drop of 1.4 dKH all at once causes a big pH drop. In my tests, it was from pH 8.1 to 6.91. Much too large.

One tenth of that drop (0.14 dKH, so about your daily alk drop) would give a much smaller pH drop. I'd roughly estimate that at about a few tenths of a pH unit. Maybe still too large to be optimal.

If you wanted to go this route, I'd try adding a 0.05 dKH drop of alk into a sump away from delicate organisms, and watch tank pH for a few hours and see how it goes. Upstream of a skimmer is good to allow it to blow off some CO2.

I'd so this with sodium bisulfate:

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

 

[rahger]

Based on my scenario and all those options what would you recommend I do as a long term solution? I’m at a loss.

 

[Randy Holmes-Farley]

Based on my scenario and all those options what would you recommend I do as a long term solution? I’m at a loss.

Do you already do water changes? If so, what size and how often?

 

[rahger]

Do you already do water changes? If so, what size and how often?

15g every 2 weeks.

 

[Randy Holmes-Farley]

15g every 2 weeks.

What percent of the total water volume is that, roughly?