Alk rising on its own - No dosing

[mbmartin06]

That is what happens when you post late and wake up early… derp

lol. Maybe there is no3 consumption and replacement in excess of the dosing. I would like to know how that works honestly

 

[Rmckoy]

So a few weeks ago I did a large water change after noticing my nitrates starting to climb again (to about 20). My alk was stable just under 8.0 dkh for a few months at this point. I was also dosing a small amount of 2-part during this time as the coraline was consuming a decent amount of alk. I use Red Sea Blue Bucket for salt.

After I did this water change, I tested a day or two after and noticed my alkalinity was over 8.0 dkh. So I stopped dosing my 2part since it was only 2.5mls a day (used to be 10ml) ever since switching to blue bucket from TMP. I also tested my NSW and got a reading of 9dkh. So I stopped doing my daily water changes for about a week to see if it would continue to climb.

My alkalinity continued to increase despite no dosing or daily water changes. I started daily water changes again since it did not seam to matter. My new batch of water even tested at only 8.4 dkh. My alkalinity today was 9dkh. I have no idea why it is climbing. The only thing of concern going on in my tank is green turf algae otherwise everything is the same.

Any thoughts or suggestions? My readings are cross-checked with my salifert alk kit as well; even though it always reads about .5 dkh lower than my Hannah; it remains consistent with the change.

Increase in nitrates will cause alkalinity to increase

 

[mbmartin06]

Increase in nitrates will cause alkalinity to increase

Isn’t it the consumption of no3 (falling ppm) that creates an increase in dKH?

 

[sanzz18]

Is there anything you guys can think of to stop this or just role with it?

 

[mbmartin06]

Is there anything you guys can think of to stop this or just role with it?

Just curious did you test the fresh saltwater you made? Is it the correct dkh?

 

[Rmckoy]

Isn’t it the consumption of no3 (falling ppm) that creates an increase in dKH?

Any time I’ve had to dose nitrates above zero the alkalinity has always increased .

@Randy Holmes-Farley explains it the best

 

[mbmartin06]

Any time I’ve had to dose nitrates above zero the alkalinity has always increased .

@Randy Holmes-Farley explains it the best

Got it. working on my understanding of this

 

[Tamberav]

I believe it is the consumption but when you dose it… typically you are doing so because you are low on nitrate… from something consuming it

I would test too off water I guess. You can still have stuff in your water and read 0 TDS… cuz hobby grade and all that.

 

[sanzz18]

Just curious did you test the fresh saltwater you made? Is it the correct dkh?

Yeah when I noticed the spike I tested the fresh saltwater and it was 9dkh. I think that is about where it was supposed to mix to, maybe a little high.

I believe it is the consumption but when you dose it… typically you are doing so because you are low on nitrate… from something consuming it

I would test too off water I guess. You can still have stuff in your water and read 0 TDS… cuz hobby grade and all that.

Test top off water for alk??

Also, do you guys think I should correct this or just let the tank do its thing? I have enough nutrients at this point for my current alkalinity I think, it just isn’t where I wanted to keep it.

Should I use muriatic acid to lower the fresh saltwater to help or let it be?

 

[mbmartin06]

Yeah when I noticed the spike I tested the fresh saltwater and it was 9dkh. I think that is about where it was supposed to mix to, maybe a little high.



Test top off water for alk??

Also, do you guys think I should correct this or just let the tank do its thing? I have enough nutrients at this point for my current alkalinity I think, it just isn’t where I wanted to keep it.

Should I use muriatic acid to lower the fresh saltwater to help or let it be?

Personally I’d leave it be for now and monitor. Time takes time and all that...

 

[GoVols]

Is he dosing anything at all into the tank now? What does blue bucket TMP salt mix alk at?

TM Pro mixes close to 7 dKH at .35ppt

Red Sea “blue bucket” comes in close to 8 dKh

@sanzz18

At one point you stated that your daily water change water was at 9, wonder if that made an effect.

Is your calcium holding stable?

Are you dosing a ph buffer?

Are your nitrates holding stable or are they on a quick decline?

 

[sanzz18]

TM Pro mixes close to 7 dKH at .35ppt

Red Sea “blue bucket” comes in close to 8 dKh

@sanzz18

At one point you stated that your daily water change water was at 9, wonder if that made an effect.

Is your calcium holding stable?

Are you dosing a ph buffer?

Are your nitrates holding stable or are they on a quick decline?

Sorry TMP I guess should be scrapped from the convo, at least pertaining to me lol. I only mentioned it to state that when I made the switch from TMP to Blue bucket, that I had to significantly lower my 2-part dosing (when I was actually doing it).

To your questions, yes it had mixed up to no 9 dkh for some reason.

Calcium has held pretty stable, when I checked a few days ago it was 440. Magnesium though has fell below 1300 now.

I am not dosing any kind of ph buffer.

Over the last couple of months, my nitrates have risen from 10 to 17-19. Not fast or a crazy rise but that was what prompted me to do a 20% water change once in between my daily changes. 8-10 months ago or so is when I did many 20% water changes to get it down from over 50-60 to 10.

 

[Tamberav]

Yeah when I noticed the spike I tested the fresh saltwater and it was 9dkh. I think that is about where it was supposed to mix to, maybe a little high.



Test top off water for alk??

Also, do you guys think I should correct this or just let the tank do its thing? I have enough nutrients at this point for my current alkalinity I think, it just isn’t where I wanted to keep it.

Should I use muriatic acid to lower the fresh saltwater to help or let it be?

Test it for alk and nitrates... doubt it is the issue but I would rule it out I guess.

 

[Randy Holmes-Farley Verified Community Expert]

Declining nitrate boosts alk. The alk boost noted here is small and may be from it, from test error, or from something else like slow dissolution of sand and rock.

 

[sanzz18]

Test it for alk and nitrates... doubt it is the issue but I would rule it out I guess.

Yeah I will definitely test that shortly. At least, like you said, it will be rules out.

Declining nitrate boosts alk. The alk boost noted here is small and may be from it, it from test error, or am from something else like slow dissolution of sand and rock.

If it is slow dissolution of sand and rock, why would that be happening?

Would you suggest anything to help this issue? Or does the tank just need to continue finding an equilibrium even though it is approaching 2 years in a few months.

 

[Randy Holmes-Farley Verified Community Expert]

If it is slow dissolution of sand and rock, why would that be happening?

Would you suggest anything to help this issue? Or does the tank just need to continue finding an equilibrium even though it is approaching 2 years in a few months.

The pH down in sand is lower than in the bulk water due to degradation of organics producing CO2.

It is pretty normal and long term reefers often need to replenish sand. The contribution to alk and calcium usually goes unnoticed unless demand is very low, where it becomes noticeable.

 

[sanzz18]

The pH down in sand is lower than in the bulk water due to degradation of organics producing CO2.

It is pretty normal and long term reefers often need to replenish sand. The contribution to alk and calcium usually goes unnoticed unless demand is very low, where it becomes noticeable.

Should I let it be or try to counter it by lowering the alk of my NSW to below 8?

 

[Randy Holmes-Farley Verified Community Expert]

Should I let it be or try to counter it by lowering the alk of my NSW to below 8?

I’d keep watching it. It may just be test error.

 

[sanzz18]

I have been tracking my parameters more closely since this post. The alkalinity continues to rise slowly. It is currently 9.4. Trend is verified with my salifert test kit as well. I had tested my magnesium on the 23rd and it was 1240. Can this play a role in the unstable/rising alkalinity?

My nitrates are hanging around 17, not much change there.

My current batch of saltwater is 8.8. I had tested my RODI water just to make sure, nothing there.

Any other thoughts?

 

[Randy Holmes-Farley Verified Community Expert]

Alk rising is unrelated to magnesium at any level.

If you are not adding alk in any way (including top off with tap water), and nitrate is stable and not being dosed, then the alk rise is likely from sand and rock dissolution.

Using a lower alk salt mix for water changes would be a good answer (you can lower alk as low as you want in new salt water), as would means of increasing alk demand in the tank (e.g., corals).