Figuring out alkalinity/calcium consumption

[sfsuphysics]

So how are some of you doing it?

Best I can figure is not dose anything for a couple days, and test your alkalinity before and after, however some issues tend to arise with doing this. First you might need a fairly accurate test kit, something on the order of 0.1 dKh resolution, I guess you could scale up the volume of water you testing, however by doing that you might make it so diluted you might not even see the color at all, is there a kit out there with a small resolution? Second, the consumption is directly related to how much there is, a tank that is lower on the alkalinity is going to have its inhabitants consume less, so I guess you need to raise your tank to the appropriate levels first (testing all three parameters, Alk,Ca, Mag) and then see what happens after a couple days.

So lets hear some other methods? Or is this THE method?

 

[Gomer]

since alk can precipitate on dosing, and that alk is a coupled value and also that we don't want to let our alk drop, I'd rather figure out effective consumption by way of finding dosing stability.

Measure alk daily for a week+
during this time, dose a balanced amount of alk/Ca.
Tweek alk/Ca till you are more or less stable in your target zone.

Knowing how much you dose, lets you know your quasi consumption.

 

[GreshamH]

Heck when I did it for mine, it only took a day to tell me the first numbers and then I repeated it for a few more days. You should be able to tell in 24 hours how much it dropped, or maybe I was able to as my water volume to coral amount is super high. I have way too much coral for how little water I have

 

[tuberider]

Since my tank consumes quite a bit of carbonate it's easy for me to log the drop in alk over the course of a couple of days, right now I loose 1.5 dKh over the course of 24 hrs, in my 40g it was upwards of 3 dKh a day. If your consumption is even across the board I'd reckon you could watch your cal drop while still supplementing your alk and convert that # to alk demand, I've never done that though.

Once I get a ballpark figure, I set my timer and monitor my alk, If I see a rise or a fall I adjust my timer accordingly.

 

[seminolecpa]

I started out with a base amount and then slowly raised it until my numbers held steady (lots of testing). Once I figured out the dose I spread out the same dose over a full day using the dosers and tweaked it slightly for any changes.

I know I don't need to tell you this but in case others are reading:

Your daily required dose can be significantly different (even if you have the same sized water volume as someone else) due to -

1) livestock load
2) salt used
3) water change frequency
4) top off frequency and method
5) other things I can't remember right now.

 

[screebo]

My initial approach was strictly caveman. (so simple a caveman can do it)

I adjusted my CA and ALK prior to dosing for CA of 440 and PH of 8.2. I then followed the suggested dosing per gallon of listed in Bulk Reef Supply's website. This translated to running dosers 46 minutes a day. That did not support my consumption so I raised it to 55 minutes a day of dosing pump action. CA and ALK are now holding. This AM the PH showed 8.3. It will be interesting to view the PH log of the Apex. I ought to be able to figure that out this PM.

 

[sfsuphysics]

I guess I should really ask is what test kits are you using and what resolution do they have? I like the API one simply because it can not get any easier, however with a resolution 1dKh not exactly accurate that accurate unless your consumption is extremely high, I don't think I have an alk consumption as much as Jeremy (3dKh per day? YIKES!)... although for all I know I might But I surely wouldn't want to wait 2 days without dosing to figure it out.

Didn't occur to me to just start dosing an amount, and test/test/test and adjust as needed is probably a lot easier than trying to physically calculate how much you're losing.

I guess my biggest problem is me using old 5g salt buckets for holding my 2 part solutions, sometimes I can not realize I'm out because they're not clear like the 1g jugs some people use. Oh well. Thought it would be a good topic to ask.

 

[screebo]

I'm using the API kit for PH and general testing and verifying the CA with a Sera kit. The Apex confirmed that the API "upper range" Ph kit is pretty much right on. The API kit gave me an aprox 8.2 and the Apex came in at 8.3. I know I'll need to calibrate the PH probe in the Apex from time to time to insure accuracy. Apex makes probe calibration oh so easy. So far, my investment in the $300+ Pinpoint CA monitor has been a waste of money. I cannot get it calibrated to give accurate results. That's still a work in progress but for $12 it's hard to beat the Sera CA kit

 

[seminolecpa]

I use API as well but my consumption is also pretty high. I go through a about 3/4 of a gallon of each in a week.

I probably have a couple of extra 1g plastic jugs if you want them.

My thoughts with the reservior amounts is you want to have enough to not have to be constantly adding but not so much that if for some reason your dosing pump were to dump the whole amount in your tank it wouldn't be a total disaster. For my system that amount is about 3/4ths of a gallon of each [ which lasts about 1 week or so]. For a smaller system the amount should clearly be less.

If I was going on a long vacation I would probably go up to a full gallon each and take my chances.

 

[sfsuphysics]

Well I have verified proof that if I dump my entire 2-part buckets into my tank that it won't kill anything (except a solar wrasse for some reason!) in fact it gives it a nice snow look

 

[screebo]

Geeze Mike! That sounds REAL SCARY :*
The Solar Wrasse probably died from fright seeing all that snowy water

 

[Gomer]

Well I have verified proof that if I dump my entire 2-part buckets into my tank that it won't kill anything (except a solar wrasse for some reason!) in fact it gives it a nice snow look

and I can confirm that 1/2 gallon of 2part into a 40g does is also survivable damn sticky mechanical timers (damn coralife...have 2 and they are both sticky and retarded...glad I got the APEX now)

 

[kinetic]

I used Salifert, tested daily and logged it. Like others, I started with the "suggested" dose amount, and went up and down until things were fairly stable =)