I've been reefkeeping for around 20 years now, and things have come a long way in that time. With the advent of auto KH testing apparatus and the keeping/ growing of dense populations of stony corals (both sps and lps), it becomes apparent that there can be quite significant KH changes throughout a 24 hour period. I recognise that there can be marginal test differences/ errors on regular testing, whether using equipment or testing manually. However, if it appears that there is a regular cycle where KH drops faster at particular times of the day and slower at other times, even with error, it would appear to me that maintaining KH stability within a swing of 1 degree KH can itself be a challenge, even with regular automated dosing.
As far as I'm aware, the majority of dosing pumps on the market allow up to 24 doses per day... but don't allow you to program differing amounts for each dose. Thus they do not help overly to combat the daily uptake differences of KH. However, I have discovered that the e-Koral doser allows you to program each pump head with 3 dosing periods daily of up to 24 doses each period... hence allowing you to increase or decrease dosing amounts to up to triple the dosing volume in any given daily period. It is also a 4 head doser, giving an extra head to either use for an additional supplement, or, in my case, to split between the KH dosing giving me 6 dosing periods of 24 doses each period.
Consequently I run the e-Koral doser during my photo-period to try to keep KH as stable as possible during that time, and I also dose Kalkwasser overnight to decrease pH drop. I find that the overnight dosing of Kalkwasser is sufficient to maintain stable KH when the reef is not photosynthesising.
When setting my dosing up I used a KH guardian testing at maximum frequency (I think it may have been around twice hourly) to try to get the most accurate picture of KH variability throughout the day. Using that information, my current KH dosing is as follows:
4 dosing periods of 24 doses each (approximately 3.8ml of Triton Core7 Alk per dose) between the hours of 8:30am and 10:00pm (so 96 doses of 3.8ml Alk solution over a 13.5 hour period).
2 dosing periods of 24 doses each (approximately 3.8ml of Triton Core7 Alk per dose) from 11:30am to 9pm (so an additional 48 doses of 3.8ml Alk solution concentrated into a 9.5 hour period where Alk uptake increases presumably due to higher photosynthetic activity).
The Kalk dosing occurs for a 11 hour period commencing at 10.30pm in the evening and stopping at 9.30am the following morning.
Even with this impressive dosing regime, I still find a daily KH fluctuation of around 1 degree KH. If all dosing is off, I think I would get a KH fall of 2-3 degrees KH within 24 hours.
My system is around 2000 litres, sps heavy with a fair amount of fragging going on at any given time (I have about 500l dedicated to frag tanks within the overall system).
I thought I'd put this thread up as there seems to be little on the subject, and I'm interested to see if others have similar experiences and observations when monitoring daily KH values multiple times throughout the day.
Picture of my system attached. It's 2 X 2m Red Sea Reefers joined on a central sump, with 4 X tanks underneath (1 tank acting as a refugium, and 3 tanks as frag tanks).
As far as I'm aware, the majority of dosing pumps on the market allow up to 24 doses per day... but don't allow you to program differing amounts for each dose. Thus they do not help overly to combat the daily uptake differences of KH. However, I have discovered that the e-Koral doser allows you to program each pump head with 3 dosing periods daily of up to 24 doses each period... hence allowing you to increase or decrease dosing amounts to up to triple the dosing volume in any given daily period. It is also a 4 head doser, giving an extra head to either use for an additional supplement, or, in my case, to split between the KH dosing giving me 6 dosing periods of 24 doses each period.
Consequently I run the e-Koral doser during my photo-period to try to keep KH as stable as possible during that time, and I also dose Kalkwasser overnight to decrease pH drop. I find that the overnight dosing of Kalkwasser is sufficient to maintain stable KH when the reef is not photosynthesising.
When setting my dosing up I used a KH guardian testing at maximum frequency (I think it may have been around twice hourly) to try to get the most accurate picture of KH variability throughout the day. Using that information, my current KH dosing is as follows:
4 dosing periods of 24 doses each (approximately 3.8ml of Triton Core7 Alk per dose) between the hours of 8:30am and 10:00pm (so 96 doses of 3.8ml Alk solution over a 13.5 hour period).
2 dosing periods of 24 doses each (approximately 3.8ml of Triton Core7 Alk per dose) from 11:30am to 9pm (so an additional 48 doses of 3.8ml Alk solution concentrated into a 9.5 hour period where Alk uptake increases presumably due to higher photosynthetic activity).
The Kalk dosing occurs for a 11 hour period commencing at 10.30pm in the evening and stopping at 9.30am the following morning.
Even with this impressive dosing regime, I still find a daily KH fluctuation of around 1 degree KH. If all dosing is off, I think I would get a KH fall of 2-3 degrees KH within 24 hours.
My system is around 2000 litres, sps heavy with a fair amount of fragging going on at any given time (I have about 500l dedicated to frag tanks within the overall system).
I thought I'd put this thread up as there seems to be little on the subject, and I'm interested to see if others have similar experiences and observations when monitoring daily KH values multiple times throughout the day.
Picture of my system attached. It's 2 X 2m Red Sea Reefers joined on a central sump, with 4 X tanks underneath (1 tank acting as a refugium, and 3 tanks as frag tanks).