Dosing Kalkwasser

[sammo2001]

Hi all,
For the last few months I have been running a 100L FOWLR tank and the pH has been fairly stable at 7.82. I am wanting to add coral pretty soon so my local fish guy has put me on to Kalkwasser. I added Kalk manually at the maximum recommended does to slowly raise the pH to 8.2 and then added 1.5tsp of Kalk to my 5L ATO reservoir to try and keep the pH stable. I let it run overnight and woke this morning to find the pH back at 7.90. Is this a normal diurnal swing or is my evaporation rate not enough and therefore I'm not adding enough Kalk?

 

[ccCapt]

pH will always be lower in the morning after the lights have been off all night and will rise during the day when the lights are on.
Keep in mind kalk will also add calcium and alkalinity so dosing it if it's not needed could lead to precipitation issues.

 

[sammo2001]

But should it drop more then 0.2 over night? I'll keep an eye on it today and see how it goes.

 

[danbstrong]

But should it drop more then 0.2 over night? I'll keep an eye on it today and see how it goes.

Ive been running my reeftank for a year at 7.9 with no adverse affects its stays this low because of calcium reactor yours may be low because of low alk or mag have you checked those lately

 

[sammo2001]

I have just ordered a chiller and alk and ca test kits. Hopefully they arrive soon as they will give me more of an idea of what's going on.

 

[sammo2001]

Ok so I've managed to keep my pH above 8.0 for the day but it is slowly trending downwards. I think I am evaporating 1-2L of water per day. Is that enough or should it be more so I can get more Kalk in?

 

[danbstrong]

Ok so I've managed to keep my pH above 8.0 for the day but it is slowly trending downwards. I think I am evaporating 1-2L of water per day. Is that enough or should it be more so I can get more Kalk in?

Imo id check the alk and mag first low alk and youll never get ph up