Kalk + AFR (in addition, not mixed)

[crabgrass]

I am going to experiment from moving away from AFR to Kalk in order to get a larger PH boost (continuous slow drip.. if possible). Its possible at this state I will meet all of my Alk/CA needs just from Kalk. As the tank matures, that may not be the case. Questions:

1. If I am just using Kalk, should I plan on supplementing some MG daily? Or would water changes every 2 weeks cover that. I know the answer is test to find out (but randy said to not test MG )

2. I don't see an issue, but If I need additional Alk/CA beyond what a continuous slow drip works out to, adding AFR separately seems like a viable option, right?

 

[Randy Holmes-Farley]

2. Yes

On 1, there’s no need to add magnesium daily. Once a week is more than often enough. It won’t drop detectably in 1 week.

Add 5-10 ppm magnesium for each 100 ppm of calcium added. High end if coralline is a major user, low end if not.

 

[crabgrass]

2. Yes

On 1, there’s no need to add magnesium daily. Once a week is more than often enough. It won’t drop detectably in 1 week.

Add 5-10 ppm magnesium for each 100 ppm of calcium added. High end if coralline is a major user, low end if not.

Thanks Randy. Two follow-up q's

1. For the mg, if I wanted to do weekly + some catch up (e.g. I am convinced my mg is a bit low), can this be added mostly all at once, or just like Alk and Ca, we should add it gradually over the course of 3 days or so?

2. Would you recommend dosing a 2 part, instead of AFR for additional PH (if needed)? I like the theoretical idea of trace elements but haven't done an ICP test to really know if its an issue or not yet.

 

[ReeferZ1227]

Thanks Randy. Two follow-up q's

1. For the mg, if I wanted to do weekly + some catch up (e.g. I am convinced my mg is a bit low), can this be added mostly all at once, or just like Alk and Ca, we should add it gradually over the course of 3 days or so?

2. Would you recommend dosing a 2 part, instead of AFR for additional PH (if needed)? I like the theoretical idea of trace elements but haven't done an ICP test to really know if its an issue or not yet.

FWIW I've been running my tank on AFR and Kalk for 2.5 years. I try to do about half and half for my daily consumption of ~2dkh. I have pretty excellent growth relative to my friends, who run their tanks differently. I recently did my first ICP after lazy WC schedule during that 2 years and mostly everything was in range except potassium 630 and calcium was 515, and the dang tin. Thats a whole nother issue.

I trusted saliferts K test and kept dosing the hell out of it. I never dosed calcium alone. Traditional kalk, says to use it to maintain and make corrections with 2 part. Long term if your lazy on WC you can expect calcium to run high IIRC, and I believe correcting alk with kalk will further raise the Ca surpluss. I use RSCP for my lazy WC schedule and that strategy seemed to be more than enough for Mg.

If you have high indoor co2, and your friends don't, you won't win those contests no matter what concotion you throw at the tank IMO. My tank took off exponentially upon correcting my indoor co2 with fresh air ventilation. High indoor co2 with SPS flow/surface agitation will scoff at kalk, scrubber/recirc, etc depending on the CO2 levels.

 

[Randy Holmes-Farley]

Thanks Randy. Two follow-up q's

1. For the mg, if I wanted to do weekly + some catch up (e.g. I am convinced my mg is a bit low), can this be added mostly all at once, or just like Alk and Ca, we should add it gradually over the course of 3 days or so?

2. Would you recommend dosing a 2 part, instead of AFR for additional PH (if needed)? I like the theoretical idea of trace elements but haven't done an ICP test to really know if its an issue or not yet.

I'd raise magnesium by 25 ppm per day or so. The concern is not the magnesium, IMO, but the potential for impurities in it.

If pH raising is a goal, then for alk and calcium I'd either use a two part or limewater/kalkwasser. One can get a two part with added trace elements, or one just intended to add calcium and alkalinity without reducing other elements.

I discuss those two part issues/choices here:

How a Two Part Alkalinity and Calcium System Works, and Why it Matters

How a Two Part Alkalinity and Calcium System Works, and Why it Matters By Randy Holmes-Farley This article is intended to help aquarists understand some of the important differences between the great variety of two and three part alkalinity and...

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