calculating dosing amounts

[krayzie]

Hi Guys

after realising i needed to start to dose alkalinity (manually) i have been testing alk every day for about a month to try and find out how much alk my tank is consuming per day but there is no consistent number that is being used per day, some times it s 0.1 sometimes its 0.2 or even more.

coming up to my second reagent of hanna alk checker has got me thinking what does everyone else do to calculate their alk consumption? manual test everyday?

weekly alk testing and dividing by 7 for a daily dose?

tank is LPS/softie

thanks

 

[tbrown]

The typically accepted and recommended way to do this is to get your alk where you want it, then wait 4 days and test at close to the same time you added the alk originally, divide the difference by 4, and that's your average daily usage. Dose that much daily at close to the same time(s). If your tests are at different times of the day, they're likely to be a little different.

 

[krayzie]

Hi tbrown, why is it 4 days? why not 7?

thanks for your reply. i always try and test and dose at the same time. 7pm if im dosing calc its normally an hour after alk

 

[tbrown]

7 days would be better, most people just do 4. My guess is that, depending on the needs of your tank, waiting 7 days can be a significant drop.

 

[tbrown]

Also, that's waiting those 4 days without dosing anything.

 

[krayzie]

that is true 7 days from 7.5 would probably crash it to under 7's and that is probably not ideal but a better sample rate

 

[Randy Holmes-Farley]

My suggested way is different than the wait test, which is not optimal, IMO.

If you think it is about 0.1 to 0.2 dKH per day, pick a dose in that range and start dosing, then after a few days (not 1 day) adjust the dose up or down as needed.