Time to start dosing?

[agamblinalot]

Think my alk converts to 7.1. I know it’s supposed to be 8-12. It was 7.6 a week ago but I added some corals. What do you all recommend to dose with? All my LFS had was Red Sea part B.

Tank is almost a month old, 15 gal hello reef AIO.

 

[Fish Fan]

Do you have a lot of coralline algae that’s consuming your Alk?

Take a look at Tropic Marin’s All For Reef (AFR), it’s a popular and easy way to dose everything you need from one bottle.

https://www.bulkreefsupply.com/all-...aulk-eS1a19V8Yas0MYzCFy_GMXlgWZRy4808BBTV-_Xq

 

[agamblinalot]

Do you have a lot of coralline algae that’s consuming your Alk?

Take a look at Tropic Marin’s All For Reef (AFR), it’s a popular and easy way to dose everything you need from one bottle.

https://www.bulkreefsupply.com/all-...aulk-eS1a19V8Yas0MYzCFy_GMXlgWZRy4808BBTV-_Xq

No coraline yet that I can see, but my alk has always been on the low side.

Yeah I was looking into AFR but my LFS said dosing is based off your CA and so it likely wouldn’t bring my Alk up enough since my CA isn’t too far off ideal.

 

[Fish Fan]

They're not wrong, AFR is more for maintaining Alk than raising it. There are other things you can dose to raise it, but what salt mix are you using and have you checked a sample of freshly mixed saltwater to see what it measures for Alk? Others do it differently, but I like to start with a salt mix that mixes to the Alk you want to run, and then maintain that level.

 

[Miami Reef]

Yeah I was looking into AFR but my LFS said dosing is based off your CA and so it likely wouldn’t bring my Alk up enough since my CA isn’t too far off ideal.

That advice is incorrect. I know that's what the bottle instructions say, but from a logical and chemical standpoint, it is clearly suboptimal.

1. Alkalinity stability is far more important than calcium stability
2. Calcium tests are not nearly as precise enough to determine slight changes.
3. Alkalinity has a much narrow safe range (7 - 11 dKH) while calcium's range is significantly greater (400 - 550 ppm)
4. AFR is slightly calcium heavy, so maintaining calcium will lead to a slight alk decline overtime.

Alkalinity and calcium has a fixed ratio in AFR. Every 2.8 dKH added will add about 20 ppm calcium (maybe a tiny bit more, but not significantly).

If you raise your alkalinity from 7.1 dKH to 9 dKH, the calcium will only increase by about 13.6 ppm.

Yes, you can use AFR to increase alkalinity.

 

[Fish Fan]

That advice is incorrect. I know that's what the bottle instructions say, but from a logical and chemical standpoint, it is clearly suboptimal.

1. Alkalinity stability is far more important than calcium stability
2. Calcium tests are not precise enough to determine slight changes
3. Alkalinity has a much narrow safe range (7 - 11 dKH) while calcium's range is significantly greater (400 - 550 ppm)

Alkalinity and calcium has a fixed ratio in AFR. Every 2.8 dKH added will add about 20 ppm calcium (maybe a tiny bit more, but not significantly).

If you raise your alkalinity from 7.1 dKH to 9 dKH, the calcium will only increase by about 13.6 ppm.

Yes, you can use AFR to increase alkalinity.

Interesting! I was told not to use it to raise Alk, but in practice when I added too much to my tank, the alk does indeed go up, I just thought I was doing something wrong

 

[Miami Reef]

There's a lot of over generalization in this hobby; however, the math never lies.

 

[agamblinalot]

Yeah I was looking into AFR but my LFS said dosing is based off your CA and so it likely wouldn’t bring my Alk up enough since my CA isn’t too far off ideal.

That advice is incorrect. I know that's what the bottle instructions say, but from a logical and chemical standpoint, it is clearly suboptimal.

1. Alkalinity stability is far more important than calcium stability
2. Calcium tests are not nearly as precise enough to determine slight changes.
3. Alkalinity has a much narrow safe range (7 - 11 dKH) while calcium's range is significantly greater (400 - 550 ppm)
4. AFR is slightly calcium heavy, so maintaining calcium will lead to a slight alk decline overtime.

Alkalinity and calcium has a fixed ratio in AFR. Every 2.8 dKH added will add about 20 ppm calcium (maybe a tiny bit more, but not significantly).

If you raise your alkalinity from 7.1 dKH to 9 dKH, the calcium will only increase by about 13.6 ppm.

Yes, you can use AFR to increase alkalinity.

Good to know! I’d much prefer to just dose one thing and I already like a lot of their other products. I’ll grab some AFR.

As a newbie it just makes life easier. How about testing? Can I get away with just testing dKH, salinity (I test this a lot cause of my water volume), and pH? If I’m doing weekly 20% water changes? My phosphate and nitrates don’t change much that I’ve noticed.

 

[Miami Reef]

You don’t need to ever test calcium or magnesium because AFR contains both in a fixed ratio with alkalinity.

I did mention it was a little calcium heavy, so you’ll get a slight increase of calcium overtime when using it to maintain alkalinity.

However, this effect is completely negated by your water change schedule. Even if you changed 10% twice a month, you will not ever need to test those parameters. The water change will naturally bring Ca and Mg toward the sea mix level.

I never test either Ca or Mg in my tank because I, like you, also use a complete additive system.

And yes, I’ve had ICP tests over the years. My calcium and magnesium are always in a safe range. That’s why I’m a big fan of water changes. You need not much to get the benefits.

 

[exnisstech]

If I’m doing weekly 20% water changes? My phosphate and nitrates don’t change much that I’ve noticed.

What is the alk on your fresh mixed saltwater? Looking at your coral I find it hard to believe that 20% weekly WCs wouldn't keep alk good unless your using a low alk salt.
This 20g runs alk mid to high 8 dkH while not heavily stocked I do minimal WC and do not dose. I do very minimal WCs as shown below.
I use IO purple which mixes 9.2ish dkH at 1.025 for me.
WCs schedule

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The tank

 

[agamblinalot]

If I’m doing weekly 20% water changes? My phosphate and nitrates don’t change much that I’ve noticed.

What is the alk on your fresh mixed saltwater? Looking at your coral I find it hard to believe that 20% weekly WCs wouldn't keep alk good unless your using a low alk salt.
This 20g runs alk mid to high 8 dkH while not heavily stocked I do minimal WC and do not dose. I do very minimal WCs as shown below.
I use IO purple which mixes 9.2ish dkH at 1.025 for me.
WCs schedule

---

The tank

Honestly I haven’t tested my salt mix. I’m a month in and my LFS gives out free rodi and only charges .75/gal for their salt water, so I’ve been using that. I did get some Instant Ocean but it’s just the standard orange one.

I’ll get a Hanna Alk checker or a salifert kit and test it out. Sounds like I’ll be testing that a lot. I do plan on getting more LPS once I get rid of my diatoms and start seeing coralline and a few more months of stable parameters.

 

[exnisstech]

I would highly recommend testing salinity and then alk on a batch of fresh saltwater purchased. I'm not a very trusting individual.

This is good budget refractometer.

That and a batch if Randy's DIY calibration fluid and your good for salinty testing.

https://reefkeeping.com/issues/2004-06/rhf/index.htm

 

[agamblinalot]

I would highly recommend testing salinity and then alk on a batch of fresh saltwater purchased. I'm not a very trusting individual.

This is good budget refractometer.

That and a batch if Randy's DIY calibration fluid and your good for salinty testing.

https://reefkeeping.com/issues/2004-06/rhf/index.htm

Thanks, I have a refractometer and brs calibration fluid. I test that all the time and my fresh mix comes in at 1.026 every time.

 

[Randy Holmes-Farley Verified Community Expert]

It would be fine to dose some AFR if you want alk higher, but it is not correct that alk needs to be at a minimum of 8 dKH. Yours is fine and is still actually higher than the ocean (mid 6’s).

I recommend 7-11 dKH.

 

[Koty]

Not sure if it was mentioned here but using AFR Alkalinity rise is delayed as it depends on bacterial activity.Regarding Mg measurment, it is a good second indication for issues with salinity. Refractometers have a wide range of quality and are useless w/o calibration.