My alk keeps dropping with afr

[Notsolostfish]

Hello everyone. Iv been doing lately awc with tropic marin pro salt i add some alk to the mix, and i also dose 95ml/afr a day seperated on hourly dose. My alk keeps dropping. I was at 8.4 like not even 2 weeks ago. Then now it dropped my alk to 7.5 its getting annoying that i have to increase afr every 2 weeks. My calcium, and mag also dropping. What product should i switch to?

I get it awc 1% a day affects it, growth, etc. but its genuinely annoying have to increase afr every 2 weeks and getting a bit pricey even for powder

 

[cdemoss01]

Tank looks great btw.

• Tropic Marin Pro Salt (great base, but low in alk)
• AFR at 95 mL/day
• AWC at 1%/day (which does dilute trace/calc/alk, especially with TM Pro’s conservative levels)

Yet your Alk is still falling from 8.4 → 7.5 within 2 weeks.

Likely Causes:​

1. Coral growth uptake is outpacing AFR (which is expected in a maturing reef).
2. AFR might be maxed out for your system size—its single-dose approach works until demand gets too high.
3. AWC with TM Pro Salt slowly lowers levels—alk of freshly mixed TM Pro is ~7.5–7.8 dKH.
4. AFR’s alk-to-calcium-to-mag ratio is fixed, which can make fine-tuning annoying.

---

What You Can Do About It​

Option 1: Switch to 2-Part or 3-Part Dosing​

If you're serious about coral growth and fine control, switching to separate dosing for alk, calc, and mag may be better:

• BRS 2-Part (or 3-Part if you're dosing mag separately)
• ESV B-Ionic
• Fauna Marin Balling Light (if you still want trace elements included)

You gain full control and better cost efficiency. Powder refills are cheaper, and you won’t be limited by AFR’s fixed ratios.

Why this is better:​

• You can bump up alk only without messing with Ca/Mg.
• You can adjust ratios to suit your tank’s growth patterns.
• You don’t run into the AFR “ceiling.”

 

[Notsolostfish]

Tank looks great btw.

• Tropic Marin Pro Salt (great base, but low in alk)
• AFR at 95 mL/day
• AWC at 1%/day (which does dilute trace/calc/alk, especially with TM Pro’s conservative levels)

Yet your Alk is still falling from 8.4 → 7.5 within 2 weeks.

Likely Causes:​

1. Coral growth uptake is outpacing AFR (which is expected in a maturing reef).
2. AFR might be maxed out for your system size—its single-dose approach works until demand gets too high.
3. AWC with TM Pro Salt slowly lowers levels—alk of freshly mixed TM Pro is ~7.5–7.8 dKH.
4. AFR’s alk-to-calcium-to-mag ratio is fixed, which can make fine-tuning annoying.

---

What You Can Do About It​

Option 1: Switch to 2-Part or 3-Part Dosing​

If you're serious about coral growth and fine control, switching to separate dosing for alk, calc, and mag may be better:

• BRS 2-Part (or 3-Part if you're dosing mag separately)
• ESV B-Ionic
• Fauna Marin Balling Light (if you still want trace elements included)

You gain full control and better cost efficiency. Powder refills are cheaper, and you won’t be limited by AFR’s fixed ratios.

Why this is better:​

• You can bump up alk only without messing with Ca/Mg.
• You can adjust ratios to suit your tank’s growth patterns.
• You don’t run into the AFR “ceiling.”

Did u ask chatgpt to write an answer and u copy and pasted it? Seriously?

 

[Tahoe61]

Did u ask chatgpt to write an answer and u copy and pasted it? Seriously?

A member took the time to offer you assistance that's what I got out of the post. The information appears correct.

 

[Notsolostfish]

A member took the time to offer you assistance that's what I got out of the post. The information appears correct.

Yeah chatgpt sounds good.

 

[Reefering1]

Can't wait for reefgtp to come out, then we won't need communities of people to talk to, for help/ answers.. :thinking-face:

 

[Reefering1]

What size tank is that? Might seem silly, but are you sure the awc isn't sucking out some afr? Awc water is taken upstream of dosing or timing offset?

 

[Notsolostfish]

What size tank is that? Might seem silly, but are you sure the awc isn't sucking out some afr? Awc water is taken upstream of dosing or timing offset?

My awc runs 2 hours 1% from 6 to 8 i dont think that 8ml is going to make a big difference.

150G total water volume

 

[fandaga]

I have the same issue. I am adding approximately 10mL AFR daily to a 47g to keep the Cal and Mg at 410 and 1340, respectively. Alk is now down at 6.1. I was previously supplementing with 10 mL daily of Brightwell alkalin8.3 to keep alk separately at 8.5. Alkalin8.3 apparently is a bicarbonate solution but has some other ions like borate that I didn’t want to keep adding. Once I stopped, alk dropped about 0.1 units daily until it stabilized at 6.1. I’m now considering slowly raising alk again to 8.5 using a sodium hydroxide solution dosed at night to also flatten out the pH swing.

 

[Miami Reef]

I am very against using ChatGPT to answer questions on the forums. If someone wanted to use ChatGPT, they’d use it themselves.

I actually made a thread about it and the staff agreed that solely using ChatGPT to answer question is not allowed. The advice is not always accurate or helpful, and sometimes it takes real experience and knowledge to answer questions…not just parroting what an AI bot says as your own words; that’s plagiarism.

The advice that All For Reef just stops working or has a cap is demonstrably false. Worst case scenario, it will just be more costly compared to other systems. It will certainly not stop working.

All For Reef is a bit calcium-heavy, but calcium is more than fine up to 550 ppm. If you really wanted to lower it, just use sodium bicarbonate until the calcium drops back down.

Anyway, the answer is to increase the dose of AFR.

 

[Fritz05]

Can't wait for reefgtp to come out, then we won't need communities of people to talk to, for help/ answers.. :thinking-face:

That would be sad. I love this community!

 

[FishTacos2]

Dose your AFR to keep calcium stable
If alk is falling than you should dose additional alk seperaty. I currently dose 40ml AFR and an additional 15ml TM Alk daily. I adjust mg when needed based on ICP results.

If cost is an issue with AFR dose 2 or 3 part as above

You can also incorporate something like calk as well as a cost effective option.

 

[Notsolostfish]

I am very against using ChatGPT to answer questions on the forums. If someone wanted to use ChatGPT, they’d use it themselves.

I actually made a thread about it and the staff agreed that solely using ChatGPT to answer question is not allowed. The advice is not always accurate or helpful, and sometimes it takes real experience and knowledge to answer questions…not just parroting what an AI bot says as your own words; that’s plagiarism.

The advice that All For Reef just stops working or has a cap is demonstrably false. Worst case scenario, it will just be more costly compared to other systems. It will certainly not stop working.

All For Reef is a bit calcium-heavy, but calcium is more than fine up to 550 ppm. If you really wanted to lower it, just use sodium bicarbonate until the calcium drops back down.

Anyway, the answer is to increase the dose of AFR.

Im going to be honest im thinking about switching to a calcium reactor, and let my awc replace traces.

 

[Rhetoric]

Interesting post. As my reef tank matures and growth demand is always going up.

"My alk keeps dropping with afr" is phrased in a way that implies it's not working?

 

[Reefering1]

My awc runs 2 hours 1% from 6 to 8 i dont think that 8ml is going to make a big difference.

150G total water volume

8Ml is almost 9% of your 96ml dose. 96ml just seems a bit high to me, for that coral load, though I don't use afr. Have you verified the amount of solution actually making it into the tank? Maybe a hose clogging up? What are the rest of you parameters?

 

[Tahoe61]

You already tried kalk right?

 

[Bartanto]

I’ve got a 150 gal at about a year old, tons of coral with great growth using TM Pro and AFR. 1% AWC. I dose 70ml of AFR and 70 ml of part B daily. Alk is always dropping. To me it must be additional consumption.

Edit: only to mention I wish I could get dosing stable in my current method, but am happy all the little fellas are growing.

 

[Danjoethepirate]

I have 130-140 gallons total system volume heavily stocked, and I use 130 ml a day. You need to up the dosage. You are not anywhere near the manufacturers stated threshold.

 

[exnisstech]

Maybe it's just me but using a salt that mixes lower than your target seems counter productive when your having to dose to raise alk.
I use AFR in my SPS tank and dose 30ml daily to 65g total volume. I have to tweak it every so often, usually to increase but occasionally I've had to reduce it if coral growth slows. Its not a set it and forget it additive IME
I target 8.5 dkH and use a salt that mixed 8.8-9.0 dkH
Your tank has a lot of coral including that big monticap so I would expect the need for AFR to increase. I had green and orange monticaps in my old tank and they were my main consumers of alk.
As mentioned there are alternatives if cost is the issue.

 

[56longroof]

Increase AFR and I'd start dosing 1/2 strength kalk in ATO. That's what I did.