Not a newbie, but help with dosing....

[hinnenkm]

So I've been in the hobby for several years now and understand the concept of dosing and in theory how to calculate the correct dosage amounts for calcium and alkalinity. I still can't get a handle on it though in real life - even though I've done a lot of reading and have gained a lot of experience over the years. 

 

Here's an example of my tank for the past 3 days....

 

June 29th: Calc 450     Alk 9.6

June 30th: Calc 425    Alk 9.6

July 1st:    Calc 440     Alk  9.2

 

I'm using the hanna checker for alkalinity and the salifert test for calcium. I have also been testing my tank at 8:30pm each time I've checked. I don't have Mg values because my test kit is apparently missing bottle 2 (it's been awhile since I've used it).

 

Any words of wisdom would be very much appreciated.

Thanks in advance!

[RayWhisperer]

Ok, nothing too out of whack there. Calcium is a little out, not bad, though. A few things to get straight, first. 

 

Are you dosing the same amounts of both product? I’m assuming yes, as the values are pretty consistent. 

What product are you using? I’ve only used a few, myself. Yet, I’ve had varied results from different products. 

Was day 1 shortly after a water change? 

How long have you been dosing?

 

Fwiw, I’d say you’re pretty well on point. Over a 3 day sampling, that’s not something I would worry about. All is in adequate amounts. Calcium is a little low, but my experience has always been anything above  370 ish is plenty useable. Alk drop of .4 isn’t huge. It’s likely a symptom of “chemistry correction”, for lack of a better term. Or, you’re seeing true uptake, now that you’ve kept values in useable ranges. 

[Clown79]

The easiest way to dose is using 2 part dosers and focusing on the alk levels not the ca.

 

With 2 part dosers you dose in equal parts to keep the alk and ca balanced.

 

So for example, I rarely test ca, I focus on alk. I dose according to my alk levels. 

 

To maintain my alk levels daily, I have to dose 1.9ml of Esv Alk buffer. I also then does 1.9 of ca buffer. 

 

Your numbers look good. 

 

Are you dosing or are the parameters over the 3 days just natural drops?

[hinnenkm]

Sorry, should have clarified. Not dosing anything - I wanted to see what the tank does naturally. The first day was right after a water change to know what starting values were. Clown79, what you were saying makes a lot of sense. Thank you and to RayWhisperer as well. I definitely appreciate the feedback!

[Aurortpa]

Interesting. Consumed 25 cal one day, then actually added 15 the next naturally?

 

How old is your rock and substrate? Did you feed any day? Do a significant top off with any saltwater?

 

 

[seabass]

Also, keep in mind that hobby test kits (even the ones you use) aren't 100% accurate or consistent.  They get you in the ballpark and let you observe trends, and are usually close enough to keep our reefs in a safe range.

 

For example: Try doing a second Hanna alkalinity test immediately after testing for it.  Chances are that the results will be different.  Still, you basically know your tank's alkalinity level.

 

I also like to compare the tank levels against a mixed batch of saltwater.  That way you can observe how much your display has strayed from those levels.  I use these salt mix levels as a target when dosing.  That way, water changes bring you closer to targets, versus fighting against some "optimal" target.

[hinnenkm]

7 hours ago, Aurortpa said:

Interesting. Consumed 25 cal one day, then actually added 15 the next naturally?

 

How old is your rock and substrate? Did you feed any day? Do a significant top off with any saltwater?

 

 

That's why I get confused - because I've tested in the past (every couple of days trying to get a handle on what the tank is doing) and had the same thing occur. That's why I decided to test daily and will continue to do so now for the next couple of days until I leave town. As far as sand, I bought the tank from a friend and just left it in there - probably two years old? The rock is relatively new, but had been curing for a few months before starting the tank. 

[hinnenkm]

3 hours ago, seabass said:

Also, keep in mind that hobby test kits (even the ones you use) aren't 100% accurate or consistent.  They get you in the ballpark and let you observe trends, and are usually close enough to keep our reefs in a safe range.

 

For example: Try doing a second Hanna alkalinity test immediately after testing for it.  Chances are that the results will be different.  Still, you basically know your tank's alkalinity level.

 

I also like to compare the tank levels against a mixed batch of saltwater.  That way you can observe how much your display has strayed from those levels.  I use these salt mix levels as a target when dosing.  That way, water changes bring you closer to targets, versus fighting against some "optimal" target.

That's fair. I did test my mixed water a while back, but didn't write it down. I will do that before the next water change. I was using Tropic Marin Bioactif though and noticed values were higher than I wanted them, so I went back to regular instant ocean and things have been within the 8-9 dkh range and calcium in the 400s. I do want to be able to dial it in better though.

[hinnenkm]

Here’s the tank, just to give everyone an idea. A few little sps as testers and mostly lps with some zoas. Thanks again for the advice!

[Aurortpa]

Beautiful tank!  🤩

 

So I suspect a 2 possibilities:

What @seabass said, simply testing error, as cal should have dropped with alk. 

or...

New liverock possibly collectively leached calcium into the water.

 

I’m going with former one tho, as the rock isn’t that fresh. 

[hinnenkm]

22 hours ago, Aurortpa said:

Beautiful tank!  🤩

 

So I suspect a 2 possibilities:

What @seabass said, simply testing error, as cal should have dropped with alk. 

or...

New liverock possibly collectively leached calcium into the water.

 

I’m going with former one tho, as the rock isn’t that fresh. 

Thank you! And I would assume that it's the first as well....

Tested last night and values were:

 

Alk 9.4 and then I decided to test again and it said 9.2...

Calc 440 (didn't test that one twice, although I probably should have. 

This is why I can't get a handle on this! How two part dosing works now makes a lot more sense though after some helpful explanations on here!