Daily Alk/Ca consumption off

[plankton]

Been monitoring my 9 month old nano tank (35 total gallons) and it consumed roughly 20 ppm Ca and 0.3 dKh per day. Using the reef calculator that would be 20.2 ml Bionic Alk and 43.7 ml Bionic Ca : nearly 2 to 1.

I'm using Hanna testkits right now to measure Ca and Alk. Does that sound weird and has anyone else observed this?

 

[laverda]

It is very possible. Just depends on what you have in your tank.i had a 29 gallon tank that used 50 ml a day. I had a clam that grew to 9” along with SPS and LPS. I am sure the clam used most of it.

 

[bigdrew]

This is a few months old, but I started a search tonight to see what others might be experiencing. I am getting 7 ppm Calc and .35 dkh per day consumption right now, which is translating to 49ml of Calcium using Calcium Chloride and 16ml of liquid Soda Ash, which is nearly 3:1.

 

[saltybees]

What’s in your tank? Normally it would be the opposite way around

 

[bigdrew]

I have 7 different SPS frags that I just added 2 weeks ago, a pocillopora, 2 devils hand corals, 2 finger leathers, a bunch of mushrooms and zoas, and a medium/large toadstool, 11 snails, 7 - 10 hermit crabs, some random little red crab, and obviously coralline algae.

I added a screenshot of my testing for the last week. I am switching to dosing 2 part from using Kalkwasser, so I am now tracking the consumption such that I can program the dosing pump for dosing throughout the day.

You think this looks like something is off?

PS. Pardon my commentary on the right. I always try to track my thoughts as I take the tests, and include some basic observations. I have an excel sheet that I've been doing that with since I opened the tank. Not perfect or scientific, but it has allowed me to trace issues back to certain times.

 

[Randy Holmes-Farley]

If, in fact, what you suggest is true and not just test error or water change effects, there is no possibility other than that you are adding alkalinity somehow. There is no possible sink for calcium that does not also consume alkalinity in the ratio of about 18-20 ppm calcium for each 2.8 dKH of alkalinity.

That addition can come in ways that may not be obvious, such as nitrate dosing, declining nitrate, top off with tap water, etc.

This has more:

When Do Calcium and Alkalinity Demand Not Exactly Balance? by Randy Holmes-Farley - Reefkeeping.com

 

[bigdrew]

Thanks Randy. Incredibly helpful. I just shut off my dosing pump as a result of your comments. I am thinking the water change affects must be driving it. I am going to monitor this on a manual, daily basis (and perhaps do 2 tests at a time while doing this) to ensure that I am getting accurate numbers.

 

[saltybees]

Sorry maybe I’m not reading it right but were you using kalk and dosing 2 part at the same time? Or you’re switching to 2 part form kalk and now there’s the issue of strange usage? I’d just test my numbers, not dose anything and wait 24 hours and see the usage like you’re planning on doing anyways. Maybe try another test kit too if it’s possible just to double check.

 

[bigdrew]

Thanks for commenting @saltybees. I switching from Kalk to 2 part. I haven’t used Kalk in about 2 weeks. I cleaned the ATO tank as best I could, but perhaps there is some dust on the sidewalls of the ATO, plus my water changes, that are causing weird numbers. Also, I think testing error could be a factor. I am using RedSea’s test kit for all testing.

I will work to get my hands on some other testing options. I bought a Hanna alk checker a while back, but haven’t used it yet, so I’ll do that and compare it to RedSea’s.

 

[saltybees]

Thanks for commenting @saltybees. I switching from Kalk to 2 part. I haven’t used Kalk in about 2 weeks. I cleaned the ATO tank as best I could, but perhaps there is some dust on the sidewalls of the ATO, plus my water changes, that are causing weird numbers. Also, I think testing error could be a factor. I am using RedSea’s test kit for all testing.

I will work to get my hands on some other testing options. I bought a Hanna alk checker a while back, but haven’t used it yet, so I’ll do that and compare it to RedSea’s.

Let us know what you find!

 

[bigdrew]

Just an update on this: I believe the readings/ratio above were based on 2 different factors: testing error and water changes.

How did I conclude this? I tested Alk and Calcium 3 different times in a row for multiple days in a row, and 1 of the 3 tests each time was wildly off. I switched to a Hanna checker for the Alkalinity tests and those were much more consistent. I disposed of the RedSea Alkalinity test after that. While doing this regular testing, I rolled the dice and only dosed 1ml of Calcium each day and 12 ml of Alk each day...

As it turns out, it appears that I am only over-dosing Alkalinity by about 5ml per day with this approach. Calcium has actually remained fairly stable with me only dosing 1ml per day. That's a ratio of 7:1 alk to calcium. I will continue to monitor. I am considering purchasing a Calcium Hanna checker, as I feel like Hanna checkers are much more consistent.

We'll see. I'll continue monitoring. My corals look good, so something is working!

 

[Randy Holmes-Farley]

Just an update on this: I believe the readings/ratio above were based on 2 different factors: testing error and water changes.

How did I conclude this? I tested Alk and Calcium 3 different times in a row for multiple days in a row, and 1 of the 3 tests each time was wildly off. I switched to a Hanna checker for the Alkalinity tests and those were much more consistent. I disposed of the RedSea Alkalinity test after that. While doing this regular testing, I rolled the dice and only dosed 1ml of Calcium each day and 12 ml of Alk each day...

As it turns out, it appears that I am only over-dosing Alkalinity by about 5ml per day with this approach. Calcium has actually remained fairly stable with me only dosing 1ml per day. That's a ratio of 7:1 alk to calcium. I will continue to monitor. I am considering purchasing a Calcium Hanna checker, as I feel like Hanna checkers are much more consistent.

We'll see. I'll continue monitoring. My corals look good, so something is working!

Thanks for the update.