When’s the best time to dose kh

[Ree0712]

Hi, just wondering if there are better times of the day to be dosing my calcium, magnesium and Alk. I thought I read it was best to dose KH at night when the lights are off but i have also read it’s best to dose just as the lights come on?

 

[Randy Holmes-Farley Verified Community Expert]

Depends on what you are dosing and how much.

 

[Ree0712]

 

[Ree0712]

My KH has been dropping recently so have a higher dosage at the moment to try and bring it back up. Also my PH seems to be dipping more than usual around 8pm at night where it never used too. It’s dropped from 8.05 to 7.75 the last few nights then came back up during the next day. I assume it’s all linked

 

[Randy Holmes-Farley Verified Community Expert]

My KH has been dropping recently so have a higher dosage at the moment to try and bring it back up. Also my PH seems to be dipping more than usual around 8pm at night where it never used too. It’s dropped from 8.05 to 7.75 the last few nights then came back up during the next day. I assume it’s all linked

What exactly are you dosing and to what size tank?

The reason this is important is for pH effects and possibly the need to spread out the dosing. .

 

[Ree0712]

fauna Marin balling light and it’s 200l. My current dosing for KH is 6 doses from midnight to 6am. This is why I think I need to change it but am not sure

 

[Randy Holmes-Farley Verified Community Expert]

fauna Marin balling light and it’s 200l. My current dosing for KH is 6 doses from midnight to 6am. This is why I think I need to change it but am not sure

OK, first, FM gives apparently incorrect information about the potency of that product, so don't rely on that for calculations.

Second, it is bicarbonate, and can be dosed any time of day since it does not provide a pH boost when first added (unlike carbonate or hydroxide products). I'd personally dose it during the light cycle, when most alk is seemingly used, instead of late night.

 

[Ree0712]

OK, first, FM gives apparently incorrect information about the potency of that product, so don't rely on that for calculations.

Second, it is bicarbonate, and can be dosed any time of day since it does not provide a pH boost when first added (unlike carbonate or hydroxide products). I'd personally dose it during the light cycle, when most alk is seemingly used, instead of late night.

Thank you for this. I will switch it up and see how I get on. What should I do about the PH fluctuations or will this sort itself out in time?

 

[Randy Holmes-Farley Verified Community Expert]

Thank you for this. I will switch it up and see how I get on. What should I do about the PH fluctuations or will this sort itself out in time?

What pH fluctuations do you see?

 

[Ree0712]

What pH fluctuations do you see?

 

[Ree0712]

It might be nothing to worry about, but just want to try and keep it stable

 

[Randy Holmes-Farley Verified Community Expert]

Daily pH changes are normal, due to photosynthesis during the day consuming CO2 and raising pH. The swing you see is mostly normal, but if you wanted to bring up the low end, you can do many things such as dosing a high pH alk additive at night, outside air to a skimmer, CO2 scrubbed air to a skimmer, etc.

The product you are dosing will have limited pH effects, so the current alk dosing and the pH are mostly unrelated.