Why wouldn't I see changes in Alkalinity and Calcium?

[Dom]

So I am trying to measure Alkalinity and Calcium consumption to program my dosing system.

24 hours after a water change, my numbers were:

Salinity: 35ppt
Temp: 23.8c
pH: 8.48
Alk: 9.8
Ca: 470

Today (4 days later):

Salinity: 35ppt
Temp:23.8c
pH: 8.51
Alk: 9.8
Ca: 490

I thought it may be a testing error, so I double checked and found the numbers to be the same.

What are some reasons that I might not see consumption?

 

[dwest]

Maybe the tank is relatively new and there is little coral or coralline algae growth?

I would measure alkalinity at the same time of day a couple times per week to see a trend.

 

[Dom]

Maybe the tank is relatively new and there is little coral or coralline algae growth?

I would measure alkalinity at the same time of day a couple times per week to see a trend.

This is a 125 (145 total volume) that is the product of combining a 40, 33 and 15 gallon tanks.

So while the tank itself is up and running about 6 months, everything placed in it is from established tanks.

I typically test weekly, but in this case more because I want to calculate the consumption rate.

I'm just finding it puzzling that there wouldn't be any consumption.

 

[Sisterlimonpot]

2 possibilities come to mind. Test results are faulty or your corals aren't taking up any calcium carbonate.

 

[Dom]

2 possibilities come to mind. Test results are faulty or your corals aren't taking up any calcium carbonate.

Well... I have tested twice to check for testing error. The numbers are consistent.

And yes, that is the question behind my post. There isn't any calcium uptake. But why?

 

[Hammertyme]

What kind of corals do you have in the tank? Do you see any coralline algae growing on your glass or rock work?

 

[Sisterlimonpot]

Well... I have tested twice to check for testing error. The numbers are consistent.

And yes, that is the question behind my post. There isn't any calcium uptake. But why?

If I were to guess, based on the limited information you provided, 6 months inside a new tank may be the reason.

Stability seems to be the key and if you're tank is new, chances are things are still fighting to find a balance. It's not a far stretch to say corals need stability to do their job and grow.

Even consolidating tanks will disrupt coral growth, that move alone might take time to stabalize. If I were to guess, while trying to find a balance, the biom is fluctuating so much that it's causing your corals to slow way down.

Can you provide more information on what corals you have, how you started the new tank? Did you have to add new substrate to the new tank? Are you seeing more temperature swings? Etc?

 

[Dom]

What kind of corals do you have in the tank? Do you see any coralline algae growing on your glass or rock work?

The tank primarily has Hammers and Zoas.

The only Coralline is on rocks which was on the rock when it was moved from another tank. I do not see any new Coralline growth.

 

[PharmrJohn]

I'm in agreement with all of the above. But I would bet more on lack of growth rather than test error. Give it some time, stabilize your tank and then you'll be able to measure your consumption (as your corals will be happy). Do your corals open up?

 

[Dom]

If I were to guess, based on the limited information you provided, 6 months inside a new tank may be the reason.

Stability seems to be the key and if you're tank is new, chances are things are still fighting to find a balance. It's not a far stretch to say corals need stability to do their job and grow.

Even consolidating tanks will disrupt coral growth, that move alone might take time to stabalize. If I were to guess, while trying to find a balance, the biom is fluctuating so much that it's causing your corals to slow way down.

Can you provide more information on what corals you have, how you started the new tank? Did you have to add new substrate to the new tank? Are you seeing more temperature swings? Etc?

I'm relying on questions to provide information. Otherwise, I may provide info that isn't germane to the conversation.

If what you say is true, I would still think that there would still be some uptake. The corals themselves are big and healthy looking. Even if there isn't any growth, I would still expect to see uptake to maintain their skeletal structure. So this is and interesting problem to solve.

The corals in question are primarily Hammers and Zoas with a few other pieces whose identity I don't know. I use crushed coral as substrate as I have high flow in the tank. I did a thorough sand rinse prior to placing it into the tank. https://www.reef2reef.com/threads/my-sand-rinse-rig.1071276/

I have a pair of titanium Finnex heaters connected to a controller which keeps the temperature at 23.8c.

I'm curious to know how substrate impacts element uptake?

 

[Dom]

I'm in agreement with all of the above. But I would bet more on lack of growth rather than test error. Give it some time, stabilize your tank and then you'll be able to measure your consumption (as your corals will be happy). Do your corals open up?

My corals are great! Big and robust looking.

And while I understand that the uptake of elements and coral growth are directly connected, my question isn't about growth but the lack of uptake. :)

 

[Troylee]

My corals are great! Big and robust looking.

And while I understand that the uptake of elements and coral growth are directly connected, my question isn't about growth but the lack of uptake. :)

How are you getting such a high ph? Are you using kalk? That would explain it all if so..

 

[Sisterlimonpot]

I'm curious to know how substrate impacts element uptake?

New substrate suggests new surfaces for bacteria to cultivate. Which disrupts stability, which can stop calcium carbonate uptake to grow new skeleton.

Add a dash of combining 2 separate ecosystems, a pinch of rinsing away bacteria from sand and you have a perfect example of a system needing to find its new balance.

It might be helpful to know how big these hammer corals are. This can also be explained by more water volume for your lps to grab from and the little that it takes may be so minute that your testing isn't showing a depletion.

 

[Dom]

How are you getting such a high ph? Are you using kalk? That would explain it all if so..

Yeah... I wondered about that pH number too.

The pH is reported by a PinPoint pH probe which is calibrated with solution monthly. I am confident that this number is accurate. Currently, I am not dosing, but relying solely on water changes. When I am dosing, I use Randy's 2-part.

 

[Dom]

New substrate suggests new surfaces for bacteria to cultivate. Which disrupts stability, which can stop calcium carbonate uptake to grow new skeleton.

Add a dash of combining 2 separate ecosystems, a pinch of rinsing away bacteria from sand and you have a perfect example of a system needing to find its new balance.

It might be helpful to know how big these hammer corals are. This can also be explained by more water volume for your lps to grab from and the little that it takes may be so minute that your testing isn't showing a depletion.

This makes sense to me. So perhaps waiting it out may be prudent.

The The Hammer corals vary in size; I have a few that are 3-4 heads and some that have dozens of heads.

 

[Sisterlimonpot]

When I am dosing, I using Randy's 2-part.

Not that it pertains, but are you using sodium hydroxide for alk?

 

[Troylee]

Yeah... I wondered about that pH number too.

The pH is reported by a PinPoint pH probe which is calibrated with solution monthly. I am confident that this number is accurate. Currently, I am not dosing, but relying solely on water changes. When I am dosing, I use Randy's 2-part.

Depending on the size of your water change I’ve noticed in my display it shocks corals for a couple days then it’s back to over drive! I think it’s all the good stuff like bacteria we remove along side the the bad stuff! I’d wait a week between tests and water changes to see the difference.. 24-48 hours just might not be enough time for everything to settle and kick back into growth mode! I was doing a 40% change once a month and it shocked my tank! Now I do a 20% every 2 weeks and I haven’t noticed the stall any more after changing water.

 

[Dom]

Not that it pertains, but are you using sodium hydroxide for alk?

The 2-Part uses Calcium Chloride and Soda Ash.

So Soda ash for Alk.

 

[Dom]

Depending on the size of your water change I’ve noticed in my display it shocks corals for a couple days then it’s back to over drive! I think it’s all the good stuff like bacteria we remove along side the the bad stuff! I’d wait a week between tests and water changes to see the difference.. 24-48 hours just might not be enough time for everything to settle and kick back into growth mode! I was doing a 40% change once a month and it shocked my tank! Now I do a 20% every 2 weeks and I haven’t noticed the stall any more after changing water.

I only have facility to a 15 gallon water change weekly. Over the course of 1 month, that amounts to about 50%.

Yes, I agree; 4 days between the water change and the test may not be long enough to show uptake.

I'm thinking I should continue to monitor for few weeks and see what (if any) changes happen.

 

[Lavey29]

Soft corals don't consume alk or cal. SPS do and LPS to a lesser degree. Would not really expect to see consumption in a 6 month tank with regular water changes but also depends on how highly stocked you are with corals too.