how much Kalk to start dosing

reefmaster70

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So, during the summer when we had more windows and screens open, my pH on my 75g tank was always between 7.8-8.1 between nighttime and daytime hours. now that it's getting colder outside, we have windows closed more, and I notice today when testing that my pH during daytime(light) hours my pH is at 7.6. I have an Apex doser, and empty dosing chamber, and a container of Kalk powder sitting here. I would LIKE to add a CO2 scrubber, but I'll have to order one, but for now, I'll get the Dos set up and start dosing Kalkwasser. Just curious how much I should start dosing today to start bringing my pH back up to around 8.0 (currently sitting at about 7.6)

Thanks
 

Garf

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So, during the summer when we had more windows and screens open, my pH on my 75g tank was always between 7.8-8.1 between nighttime and daytime hours. now that it's getting colder outside, we have windows closed more, and I notice today when testing that my pH during daytime(light) hours my pH is at 7.6. I have an Apex doser, and empty dosing chamber, and a container of Kalk powder sitting here. I would LIKE to add a CO2 scrubber, but I'll have to order one, but for now, I'll get the Dos set up and start dosing Kalkwasser. Just curious how much I should start dosing today to start bringing my pH back up to around 8.0 (currently sitting at about 7.6)

Thanks
Depends on your daily alkalinity consumption and tank evaporation.
 

Red_Beard

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You will need to adjust your dosage based on alkalinity in the tank. Do you happen to know your daily alk consumption? If you do, start there using the calculator below to determine how much you need to dose to keep things stabile. If you don't, start by getting a baseline daily alk usage. Measure your alk levels, and 3 - 7 days later measure it again. Divide the difference by number of days for daily usage. Ex. measure day 1: 8.3, measured day 5: 7.8. the difference between the 2 is .5, measured across 5 days for total usage of .1dKh/day.

 

Miami Reef

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In general, it’s very difficult to maintain elevated pH if there isn’t much demand and alkalinity consumption.
 
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reefmaster70

reefmaster70

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If you aren't really consuming alk is there anything in the tank being affected by the lower pH that makes it worth even addressing?
not really...everything looks great for corals, and fish. I just don't like my pH at 7.6. My Alk has been continually staying between 10.5-11dkh, which I know isn't bad, but it's a tad high. Tank has been only up and running since June. pH normally swings between 7.7-8.2pH. I only have 3 small SPS frags, a Birdsnest a small pocillapora, and a small green montipora. My Alk literally never changes, and I test weekly.
 

Miami Reef

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Atkinson et al. (1995) maintained and grew 57 different stony corals long term at the Waikiki Aquarium in Hawaii. The incoming water ranged from pH 7.5 to 7.8, and the aquarium itself maintained a pH range of 7.6 to 8.3. Despite frequent exposure to the very low end of the scale, the corals’ growth rates were similar to the upper rates reported from the field.

From my article:
 

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