calling all AFR users

[Randy Holmes-Farley]

My mistake I thought it dealt with different minerals

AFR adds many things, but if you just want elements other than alk/Ca/Mg, then a product such as Tropic Marin A and K is a reasonable choice.

 

[smitten with ocean life]

oh boy. now im really confused. lol

 

[Troylee]

I dose 200ml daily on my 300 sps tank.. I also top off with 3 gallons of fully saturated kalk. My alk demand is crazy lol..

 

[Luminous74]

In general, you should dose AFR in a way that you don’t exceed your desired maximum values for KH or Ca. You can take the effect of water changes into account as well. Ideally, the tank consumes KH and Ca in roughly the same ratio in which AFR supplies them. If that’s not the case, you simply supplement the part that AFR doesn’t fully cover with an additional product that raises either KH or Ca only.

From what I can see, calcium is the parameter that determines your AFR dose. The missing alkalinity is then adjusted by the KH Guardian – this should work as long as the AFR dose remains stable.

If you adjust the AFR dose, the KH Guardian should adapt to the new baseline shortly afterwards. Once KH becomes the more relevant parameter, you can also let the KH Guardian control the AFR dosing. This should work well as long as AFR is roughly dialed in and you let the device measure and dose only, for example, twice a day.

My 30-liter LPS tank requires about 13 ml of AFR per day, split into 12 small doses.
By the way, 5 ml of AFR raise the alkalinity by about 0.28 dKH in 100 liters.

 

[smitten with ocean life]

ok makes sense. i have mine dosing 16.5 once a day. maybe i should try to break it down into more times a day instead of once a day

 

[Luminous74]

ok makes sense. i have mine dosing 16.5 once a day. maybe i should try to break it down into more times a day instead of once a day

I think you can do that. During the transition phase, I would let the KH Guardian measure and dose only once per day for two or three days, until the AFR dosing has settled in. After that, you can increase the measuring frequency again.

 

[Randy Holmes-Farley]

From what I can see, calcium is the parameter that determines your AFR dose. The missing alkalinity is then adjusted by the KH Guardian – this should work as long as the AFR dose remains stable.

That is not how I recommend using it. I know TM does, but I think that can lead to problems with the lack of precision and accuracy in calcium testing. I think dosing based on alk is much better.

 

[Randy Holmes-Farley]

ok makes sense. i have mine dosing 16.5 once a day. maybe i should try to break it down into more times a day instead of once a day

Since AFR releases alk slowly, I don't think spreading it out is necessary, and I would not dose at night since it consumes O2.

 

[Freenow54]

AFR adds many things, but if you just want elements other than alk/Ca/Mg, then a product such as Tropic Marin A and K is a reasonable choice.

Thanks I finally got it through my thick head

 

[Troylee]

Since AFR releases alk slowly, I don't think spreading it out is necessary, and I would not dose at night since it consumes O2.

I dose it over 24 hours.. couldn’t tell ya if there’s a difference or not.

 

[Luminous74]

That is not how I recommend using it. I know TM does, but I think that can lead to problems with the lack of precision and accuracy in calcium testing. I think dosing based on alk is much better.

I have a question to better understand your recommendation:

If calcium slowly increases over a longer period of time, does this mean that the AFR dose should be adjusted so that the long-term calcium trend remains stable, while relying mainly on alkalinity measurements in the short term?

For example:
– setting the AFR dose based on the long-term calcium trend
– and using the daily alkalinity measurement for fine-tuning (e.g., allowing a controlled drop of about 0.2 dKH per day, which is then corrected with another product)

How would you approach this situation?
I hope I expressed myself clearly.

 

[Randy Holmes-Farley]

I have a question to better understand your recommendation:

If calcium slowly increases over a longer period of time, does this mean that the AFR dose should be adjusted so that the long-term calcium trend remains stable, while relying mainly on alkalinity measurements in the short term?

For example:
– setting the AFR dose based on the long-term calcium trend
– and using the daily alkalinity measurement for fine-tuning (e.g., allowing a controlled drop of about 0.2 dKH per day, which is then corrected with another product)

How would you approach this situation?
I hope I expressed myself clearly.

My recommendation is to dose AFR in an amount sufficient to maintain your target alk. If you choose to measure calcium (I do not since I think it unnecessary when dosing just AFR) then IF it gets above 550 ppm and is still rising, then I’d back off on the AFR dose and use baking soda or other alk additive for a portion of the alk demand. That will stop the calcium rise and/or allow it to fall.

I don’t think the calcium rise is going to be excessive in most tanks getting regular water changes with a normal or low level of calcium. The water change will keep it under control. Folks see it rising through the 400s and worry, but needlessly so, IMO.

A tank dosing a huge amount of AFR or a tank with no water changes will be more likely to show an issue and need to dose a small part of the alk by normal alk additive.

I did this for 20 years in my old tank dosing kalk at 2 dKH per day. It has an identical alk to calcium ratio as AFR, and doing 1% daily water change with IO, calcium stabilized at 450 ppm.

Can it work to set the dose on calcium? Yes. But it is more prone to excessive jiggering of the dose as the calcium test result wobbles around due to salinity changes and mostly, test inaccuracy. That then may cause a big swing in alk, when it was just a small change in calcium. A correction of a 20 ppm change/error in calcium results in a big 2.8 dKH swing in alk.

 

[Luminous74]

My recommendation is to dose AFR in an amount sufficient to maintain your target alk. If you choose to measure calcium (I do not since I think it unnecessary when dosing just AFR) then IF it gets above 550 ppm and is still rising, then I’d back off on the AFR dose and use baking soda or other alk additive for a portion of the alk demand. That will stop the calcium rise and/or allow it to fall.

I don’t think the calcium rise is going to be excessive in most tanks getting regular water changes with a normal or low level of calcium. The water change will keep it under control. Folks see it rising through the 400s and worry, but needlessly so, IMO.

A tank dosing a huge amount of AFR or a tank with no water changes will be more likely to show an issue and need to dose a small part of the alk by normal alk additive.

I did this for 20 years in my old tank dosing kalk at 2 dKH per day. It has an identical alk to calcium ratio as AFR, and doing 1% daily water change with IO, calcium stabilized at 450 ppm.

Can it work to set the dose on calcium? Yes. But it is more prone to excessive jiggering of the dose as the calcium test result wobbles around due to salinity changes and mostly, test inaccuracy. That then may cause a big swing in alk, when it was just a small change in calcium. A correction of a 20 ppm change/error in calcium results in a big 2.8 dKH swing in alk.

Thank you very much for your detailed reply. In my own tank, your explanation fits perfectly. I dose AFR based on alkalinity consumption, and my calcium level has remained stable at around 450 ppm since I started using AFR (almost two years now). I do weekly water changes of about 10% with a salt that has natural calcium levels of around 425 ppm. Because of that, my former habit of testing calcium weekly has turned into an occasional check — mostly for my own peace of mind, as I now understand thanks to your explanation.

 

[smitten with ocean life]

can i snag you too @Randy Holmes-Farley ? so if i am not dosing baking soda for the alk and my cal and mag numbers are still low, do i bump up the AFR? i have a bigger system now, so im struggling to find my sweet spot

 

[JaaxReef]

I dose 92ml/day in my 120 mixed reef. I do have a Maxima clam and noticed I had to bump up about 10% when I added it.

Alk stays around 7.8, calcium 420, and mag usually a bit high around 1480. I have made minor adjustments based on ICP, but most things have stayed on track for me. I do also dose potassium based on test results at least once a month if it drops below 380.

 

[Hemmbone20]

can i snag you too @Randy Holmes-Farley ? so if i am not dosing baking soda for the alk and my cal and mag numbers are still low, do i bump up the AFR? i have a bigger system now, so im struggling to find my sweet spot

What are your parameters.
What is your alk, calcium, and magnesium

 

[Ziggy17]

So I was getting calcium and mag creep up when I used Alk to determine my aFR dose. I now use AFR to maintain calcium and dose alk and K+ separately. . The calcium I measure with Salifert test kit once a week, so I think it’s a decent reading. My mag will stay in line if my Calcium stays in line, but I check mag once a month to see where it’s at. I make my own ALK and the K+ is cheap as I only dose 15cc per day. So it’s not expensive to run all 3 through my doser and everything stays pretty steady. Every 3 or 4 weeks I do a 10% WC.

 

[smitten with ocean life]

What are your parameters.
What is your alk, calcium, and magnesium

mag is 1140
cal. 400
alk. 9.3

 

[Randy Holmes-Farley]

can i snag you too @Randy Holmes-Farley ? so if i am not dosing baking soda for the alk and my cal and mag numbers are still low, do i bump up the AFR? i have a bigger system now, so im struggling to find my sweet spot

No. You cannot use any balanced alk and calcium method (AFR, kalkwasser, CaCO3/CO2 reactor, etc.) to make significant calcium (or magnesium) changes since alk will shoot through the roof. A 20 ppm boost to calcium will boost alk by 2.8 dKH.

Use separate additives for those, although I would be wary of making magnesium changes without strong confirmation since mag testing is so often inaccurate and often it is a salinity issue. . Before believing mag is low, at least test your salt mix.

This has more on the magnesium issue:

Just say NO to magnesium testing: RMM is born

OK, this thread has been many years in the making, and I'm posting it here since folks in the chem forum are probably already tired of all the threads relating to problematic magnesium testing. I'm going to propose a method, let's call it the Randy Magnesium Method, or RMM for short. All good...

www.reef2reef.com

 

[smitten with ocean life]

thanks randy! im not trying to argue and im sure youre right, but then what is the point of AFR if you have to keep dosing other things separately? just trying to understand