Why is my alkalinity increasing?!?!

[gabesreef]

Haha yes I’m stumped as well! So when it comes to testing with the Hanna checker it’s a yes to everything except the 10ml syringe. I’ve been filling to the line because my 10ml syringe must not be accurate it always goes over the line on the glass. So I’ve been just filling to the line. Other then that yes it’s the same reagent bottle, I wipe clean finger prints, the 1ml reagent stays in the tip.

 

[SliceGolfer]

Hanna cuvettes are off!!

I have been using a 10ml syringe to accurately fill my cuvette for awhile with no problem. I recently bought new cuvettes from saltwateraquarium.com they came and they weren't the same as the old ones and fill past the 10ml line. I thought maybe I got some bad cuvettes so I ordered more from...

www.reef2reef.com

 

[gabesreef]

I’ve mixed my salt the same for a while now. I make my RODI water 10g, add my power head and mix in 5 cups of salt. I wait and test salinity. Once i’m 100% it’s at 1.025 I let it sit over night for use the next day. Before I’m going to use it I re test salinity and test alk. Never had any issues with this method but idk never had my alk creeping up either haha

 

[gabesreef]

Hanna cuvettes are off!!

I have been using a 10ml syringe to accurately fill my cuvette for awhile with no problem. I recently bought new cuvettes from saltwateraquarium.com they came and they weren't the same as the old ones and fill past the 10ml line. I thought maybe I got some bad cuvettes so I ordered more from...

www.reef2reef.com

Thank you I guess my syringe was accurate! Well anyways it shouldn’t matter because I’ve been consistently filling to the line. Therefore the alk is still creeping upwards. But I will re test in the morning to get the accurate reading thank you.

 

[schuby]

Alkalinity naturally fluctuates throughout each day. If you measure at different times, then you may get higher or lower values. I always measure my parameters at 7pm.

 

[gabesreef]

Alkalinity naturally fluctuates throughout each day. If you measure at different times, then you may get higher or lower values. I always measure my parameters at 7pm.

That’s true I typically do the first test in the afternoon and the other test at night so maybe since the Coral’s are not actively using it that’s the issue showing an “increase”.... I’m going to test today around 3pm to see if this true. thank you!

 

[Randy Holmes-Farley Verified Community Expert]

Alkalinity naturally fluctuates throughout each day. If you measure at different times, then you may get higher or lower values. I always measure my parameters at 7pm.

No it doesn't. pH fluctuates. Alkalinity does not, unless you cause fluctuation by dosing intermittently.

 

[Randy Holmes-Farley Verified Community Expert]

Tested my talk after water change 8.3 one week later I’m testing again 8.7?!? This has been going on for a while why am I getting this constant increase in alkalinity! I mix
My water over 24 hours so salt is completely dissolved.

Alkalinity can rise for a number of reasons, and in a tank with little to no demand, these minor processes become more apparent.

Declining nitrate will boost alkalinity, some additives will boost it when they claim not to or do not mention it, and sand and rock can slowly dissolve deep down inside them where the pH may be low enough due to organic degradation to dissolve some calcium carbonate.

 

[schuby]

I was surprised by how much it changes throughout the day. If you find some member's Trident Alk graphs for a week, you'll see the variation. Once they start Trident-based dosing, the fluctuation is much less.

 

[schuby]

Randy, here's one of several sample threads that I based my opinion that alkalinity naturally fluctuates throughout each day: https://www.reef2reef.com/threads/trident-hands-on.596716/post-6079380

I try not to give any chemical or scientific proof. I'm no chemist or scientist. I greatly respect your all your post. Your insights are very much appreciated.

My primary purpose with my statement is that the alkalinity value in our tanks is not constant throughout the day.

 

[Randy Holmes-Farley Verified Community Expert]

Randy, here's one of several sample threads that I based my opinion that alkalinity naturally fluctuates throughout each day: https://www.reef2reef.com/threads/trident-hands-on.596716/post-6079380

I try not to give any chemical or scientific proof. I'm no chemist or scientist. I greatly respect your all your post. Your insights are very much appreciated.

My primary purpose with my statement is that the alkalinity value in our tanks is not constant throughout the day.

Sorry, your interpretation is incorrect.

He is dosing constantly and alk is consumed not constantly, hence alkalinity fluctuates.

Alk does not itself fluctuate without dosing.

 

[gabesreef]

Sorry, your interpretation is incorrect.

He is dosing constantly and alk is consumed not constantly, hence alkalinity fluctuates.

Alk does not itself fluctuate without dosing.

I’m not dosing any alkalinity to the tank

 

[gabesreef]

In regards to the low demand this is true. My tank is mostly LSP and soft coral. So demand is rather low. I’m going to preform the test and add my results now

 

[schuby]

How about these revised, fully-qualified statements?

In our reef tanks, with growing, hard corals and a strong light that is on for a portion of each day(maybe around 8 hours), where alkalinity and calcium is dosed throughout the day in the approximate amount that is consumed each day by the tank, the alkalinity value measured by the Hanna Saltwater Aquarium Alkalinity Colorimeter (ppm) will vary. Assuming all light sources turn on and off, with the same intensity and spectrum values each day and that all feedings occur at the same times-of-day with the exact same amount and types of food, then measuring alkalinity at the same, single time-of-day will yield the most consistent values. Conversely, with the same, afore-described environment, measuring alkalinity at differing times of day will yield inconsistent values. Using more consistent, measured values of alkalinity help us make better choices about the alkalinity level in our tanks.

In general, I believe that replies on each thread should be interpreted in the context of the thread. I don't think it should be necessary to fully-qualify every reply. I'm sure that I missed some factors in the previous paragraph that directly or indirectly affect alkalinity at any moment in time.

My intended meaning of the word "naturally" is more along the line of "as a result of the living things and all the things we do to our tanks every day". Our interpretations differed, but your explanation was much more precise (mine lacked any cause). We both said "alkalinity fluctuates".

Thank you, RHF. I've learned so much from you on many threads and articles. I expect to learn much more.

 

[gabesreef]

I just tested again using the syringe. 8.7 again so nothing has changed therefore we can eliminate time of day and testing error. I’m still stumped

 

[Randy Holmes-Farley Verified Community Expert]

I’m not dosing any alkalinity to the tank

I wasn't referring to you. i was referring to his posted thread that purported to show fluctuating alkalinity.

 

[Randy Holmes-Farley Verified Community Expert]

How about these revised, fully-qualified statements?

In our reef tanks, with growing, hard corals and a strong light that is on for a portion of each day(maybe around 8 hours), where alkalinity and calcium is dosed throughout the day in the approximate amount that is consumed each day by the tank, the alkalinity value measured by the Hanna Saltwater Aquarium Alkalinity Colorimeter (ppm) will vary. Assuming all light sources turn on and off, with the same intensity and spectrum values each day and that all feedings occur at the same times-of-day with the exact same amount and types of food, then measuring alkalinity at the same, single time-of-day will yield the most consistent values. Conversely, with the same, afore-described environment, measuring alkalinity at differing times of day will yield inconsistent values. Using more consistent, measured values of alkalinity help us make better choices about the alkalinity level in our tanks.

In general, I believe that replies on each thread should be interpreted in the context of the thread. I don't think it should be necessary to fully-qualify every reply. I'm sure that I missed some factors in the previous paragraph that directly or indirectly affect alkalinity at any moment in time.

My intended meaning of the word "naturally" is more along the line of "as a result of the living things and all the things we do to our tanks every day". Our interpretations differed, but your explanation was much more precise (mine lacked any cause). We both said "alkalinity fluctuates".

Thank you, RHF. I've learned so much from you on many threads and articles. I expect to learn much more.

Alkalinity generally only declines or is stable. It does not generally rise except in unusual scenarios where demand for consumption is very low and other unusual processes are adding it.

pH and ORP are the ONLY parameters we normally measure where they would fluctuate routinely through a 24 h period independent of an aquarist's actions.

If an aquarist is dosing alkalinity in a pattern that does not exactly match the pattern of consumption, then it will fluctuate as those two patterns interact, even if the total demand for a 24 h period is exactly met.

In this case, the OP says his alk is nearly totally steady. I wouldn't even say he has demonstrated a rise since we are talking about 0.4 dKH "rise" over a whole week, but even so, assuming he is not dosing, that is not likely to be a time of day effect. His alk is not going up and down 0.4 dKH during the course of a day on its own.

 

[Randy Holmes-Farley Verified Community Expert]

I just tested again using the syringe. 8.7 again so nothing has changed therefore we can eliminate time of day and testing error. I’m still stumped

Well, maybe. You cannot reverify the first reading, and most kits will have some reasonable amount of uncertainty.

I'm not claiming it is test error, but it could well be. The Hanna alk checker only claims +/- 5% accuracy. 8.6 +/-0.4 dKH fits their accuracy claim and your results exactly.

 

[gabesreef]

Alkalinity generally only declines or is stable. It does not generally rise except in unusual scenarios where demand for consumption is very low and other unusual processes are adding it.

pH and ORP are the ONLY parameters we normally measure where they would fluctuate routinely through a 24 h period independent of an aquarist's actions.

If an aquarist is dosing alkalinity in a pattern that does not exactly match the pattern of consumption, then it will fluctuate as those two patterns interact, even if the total demand for a 24 h period is exactly met.

In this case, the OP says his alk is nearly totally steady. I wouldn't even say he has demonstrated a rise since we are talking about 0.4 dKH "rise" over a whole week, but even so, assuming he is not dosing, that is not likely to be a time of day effect. His alk is not going up and down 0.4 dKH during the course of a day on its own.

Thank you so do you think its a problem or should I just not worry about it? I’ve never had my alk increasing before so I don’t know. My only concern is my salt mixes to 8 typically, so when I do my water changes I’m essentially creating a mini drop in alkalinity every week. For example my alk is at 8.7 today if I do my water change which is at 8 I’m going to create a drop in alk. Last time I did this I tested a few hours latter and my tank was sitting at 8.3. That is .4 of a drop within a few hours.

 

[gabesreef]

Well, maybe. You cannot reverify the first reading, and most kits will have some reasonable amount of uncertainty.

I'm not claiming it is test error, but it could well be. The Hanna alk checker only claims +/- 5% accuracy. 8.6 +/-0.4 dKH fits their accuracy claim and your results exactly.

Yes this is true