About to start 2 part dosing...

[fishez4alivin]

I recently ordered a new Profilux dosing unit, and have begun to make the switch from my calcium reactor/kalk reactor combo, to dosing BRS recipe 1. For the past week, I have tested in the morning, then removed my reactor offline, and tested 24 hours later. I also did test in the late afternoon, to ensure there wasn't going to be any difference. Both days I started out with Ca readings of 425 on a Lamotte. And 24 hours later tested and found my Ca at 395. According to BRS's calculator, I am supposed to dose 337 ml of Ca. Now for my alk, I measured at the same times and found my alk to hold at 150 ppm, and 24 hours later, it was at 140ppm. According to BRS, I am supposed to dose 44ml of alk a day, to keep my levels.

Is that normal to have to dose 8.5X more Ca than alk? I have actually tested my alk 5 days and found my levels to drop only 10 ppm a day. For those who dose, are your ratios around 1:1, or is it 2:1 or higher?

TIA

 

[bertoni]

The ratio of consumption is around 50 ppm alkalinity to 20 ppm of calcium. The rest of the measurement difference you're seeing likely is just noise. I'd try dosing the 44 ml per day of each solution and see how it goes, long term.

 

[fishez4alivin]

This is in a SPS dominated tank that has a system volume of ~125G

 

[bertoni]

If you're dosing at a ratio other than 1:1, maybe there was a mixing error, but there's enough noise in our calcium test kits that your numbers are fairly reasonable, even with a correct 2-part.

The consumption can't continue at 2:1 or 8:1 calcium to alkalinity over time unless there's a problem with the BRS solutions. The chemistry won't work, well, unless there's another source of alkalinity or calcium involved. Does the tank get tap water for topoff? How about any pH buffers or other dosing?

 

[fishez4alivin]

No other dosing

 

[bertoni]

Okay, then I'd just watch the levels for a few days worth of tests. Which Ca kit are you using? What's the resolution?

 

[fishez4alivin]

Im using a LaMotte test kit, it's not like the Salifert where you have a choice of high or low resolution test., I double checked using a high resolution Salifert, and it was reading a little lower, 420 and 24 hours later 390.

 

[bertoni]

Okay, I'd just keep careful records of the dosing and the results of testing, going forward, and get a good trend line. It's easiest if you test at the same time each day that you test.

 

[fishez4alivin]

So far dosing 18 ml of Ca 20 times a day, and 6 ml 20 times daily of Soda Ash, has kept my levels at Ca 425 and 150 ppm Alk. I've been testing at 0700 and at 1800 the past few days.

 

[bertoni]

Okay, as long as the numbers seem fine, I wouldn't worry much.

 

[fishez4alivin]

Ok, great....numbers seem to be right where I want them.