How fast can I safely drop Alk?

[AFHokie]

I’ve been struggling with keeping my Alk from creeping up despite zero dosing so I’m going to bring it lower overall so I have more of a buffer. I keep my nutrients on the lower side and my corals don’t like it when I don’t do a water change quick enough to bring all back down.

I can reduce my new water to 0 dKH with Muriatic acid but I’m not sure how fast I can reduce tank Alk with water changes before I adversely affect my coral.

What is a safe speed to lower my alkalinity? I’ve dropped it as much as 0.3 in one water change but haven’t done that in rapid succession. Can I drop it .3-.5 at a time every other day or so? Right now I sit around 10.2 on average but my new salt I’m moving to is 8 and I’d prefer to be close to that.

The problem is I can’t just let it come down over time. If I don’t do a water change in 3-4 days my Alk typically climbs back .2-.3 dKH to where it was before I reduced it by .3 or so from a low Alk water change.

 

[blaxsun]

Skip a water change or two…?

 

[Chriokid79]

I personally have never experienced or even heard of alk climbing unless you are doing some form of dosing. I dont think this is possible. Are you using an ATO system and adding fresh water back to your system? If so, are you using kalk in it? Are you running a calcium reactor? Is your salinity also climbing as well?

 

[((FORDTECH))]

I think I’ve recently heard something about peoples tap water having alk in it that gets past rodi system and when used as top off it raises alk

 

[AFHokie]

Skip a water change or two…?

The problem is my water changes are made with 5 dKH water, to bring my Alk down. When I don’t do changes it increases.

I personally have never experienced or even heard of alk climbing unless you are doing some form of dosing. I dont think this is possible. Are you using an ATO system and adding fresh water back to your system? If so, are you using kalk in it? Are you running a calcium reactor? Is your salinity also climbing as well?

There are a few reasons why and it’s actually a FAQ. Dr. Holmes-Farley even recently posted a chemistry thread on it. The problem is that none of his causes in my tank check out…except the possibility of sand leaching alkalinity due to low pH under the surface. I also cannot absolutely rule out that my ATO tank wasn’t corrupted with a bit of saltwater. Even a tiny bit would make my top off higher than 0 Alk.

I dose nothing, have checked my top off water to verify both 0 TDS and 0 alkalinity (prior to filling reservoir). One drop on salifert and it changes color.

Salinity does not rise. I do not run a reactor.

That all being said, I just got back from a few days away and ran all my tests. My alkalinity actually dropped! First time in at least two months that I haven’t seen an increase after 3-4 days.

If that Alk depletion holds I’m good to go, I’ll just do my water changes with my new water at 8 and let it come down.

 

[Garf]

Alk typically climbs back .2-.3 dKH to where it was before I reduced it by .3 or so from a low Alk water change.

Nah. Are you reading your all test upside down, summit daft like that?

 

[Chriokid79]

Cool, good to hear. To your question, if it were me I would continue to monitor it dropping to the value youre looking for then start water changes again. Water changes dont keep up with my alk demand though. Honestly, I havent noticed drastic changes in alk negatively affect anything other than sps. Do you have sps?

 

[Uncle99]

Are you sure MG is in the 1350-1400ppm.
Low MG results in unstable Alk readings.

 

[AFHokie]

Nah. Are you reading your all test upside down, summit daft like that?

No.

I’ve done hundreds of tests and I would have to be amazingly lucky to be able to measure Alk, calculate how much muriatic acid I need, remeasure my Alk and somehow end up with exactly the target I expected. Oh, and then after doing to water change come out with the new target Alk.

Are you sure MG is in the 1350-1400ppm.
Low MG results in unstable Alk readings.

No, mine is usually 1300-1350. I’ve not heard of that affecting Alk but definitely something to look into. Thanks.

 

[Uncle99]

How far would it rise…above 12dkh?
I run 11.5 to 12.2dkh for 5 years.
Sometimes it’s better to run at the level the system likes for stability sake.

 

[Gatorpa]

I think I’ve recently heard something about peoples tap water having alk in it that gets past rodi system and when used as top off it raises alk

They may be a possibility or if it’s ultra hard well water.

 

[Garf]

No.

I’ve done hundreds of tests and I would have to be amazingly lucky to be able to measure Alk, calculate how much muriatic acid I need, remeasure my Alk and somehow end up with exactly the target I expected. Oh, and then after doing to water change come out with the new target Alk.

No, mine is usually 1300-1350. I’ve not heard of that affecting Alk but definitely something to look into. Thanks.

Well, your doing something wrong. Perhaps your at the peak of the first dunning Kruger curve.

 

[AFHokie]

Cool, good to hear. To your question, if it were me I would continue to monitor it dropping to the value youre looking for then start water changes again. Water changes dont keep up with my alk demand though. Honestly, I havent noticed drastic changes in alk negatively affect anything other than sps. Do you have sps?

I do have SPS. Leptos, acros, porites.

The canary in the coal mine for me is actually my DEFCON cyphastrea. If my Alk starts to climb too high without nutrients also climbing I’ll start to notice tissue pulling back and white skeleton showing. Once I get the Alk stable it regrows I’m just a day or two.

 

[amazongb]

Have your verified the increase with multiple test kits?

 

[AFHokie]

Well, your doing something wrong. Perhaps your at the peak of the first dunning Kruger curve.

So I’m experiencing an effect that gets asked about so much that @Randy Holmes-Farley wrote an entire thread about it but I’m some kind of idiot that doesn’t know how to use a Salifert kit?

So all my other salifert tests are just fine, and measure as expects but somehow I can’t use the alkalinity one? Or that, as I said, when I use simple math like .123ml/gallon of muriatic acid to drop 1 dKH that somehow I know how to use the test kit then? But not when I’m measuring my tank water?

I have explored this issue in great depth and not been able to pinpoint my cause. That is why this thread is titled asking how fast I can drop alkalinity, not why is my alkalinity increasing.

Perhaps you are experiencing the Dunning-Kruger effect with your ability to read a post and actually answer the question being asked rather than spout off how much you know about something I didn’t ask about.

Oh, and you can also tell Dr RHF he’s an idiot for saying there are ways Alkalintiy can increase, especially when tank demand is low enough to not compensate for other natural processes.

 

[AFHokie]

How far would it rise…above 12dkh?
I run 11.5 to 12.2dkh for 5 years.
Sometimes it’s better to run at the level the system likes for stability sake.

I never let it free ride to see how far it would go since I’d start seeing coral reacting poorly when it hit around 10.5.

Now….I fully realize there could be other factors since, like you said, many people run much higher alkalinity. The first time I figured it was coincidence but after it started repeating itself I figured there had to be something to it.

Still could be secondary factors but when I keep it closer to 9.5-10 everything just seems happier.

 

[AFHokie]

Have your verified the increase with multiple test kits?

I haven’t actually. Could be a poor assumption but since I see a repeatable variance and am able to measure new water around 5 I did not think it would be the kit.

If I continue to see problems I will put that on the top of the list to try and continue narrowing down the cause.

 

[Garf]

So I’m experiencing an effect that gets asked about so much that @Randy Holmes-Farley wrote an entire thread about it but I’m some kind of idiot that doesn’t know how to use a Salifert kit?

So all my other salifert tests are just fine, and measure as expects but somehow I can’t use the alkalinity one? Or that, as I said, when I use simple math like .123ml/gallon of muriatic acid to drop 1 dKH that somehow I know how to use the test kit then? But not when I’m measuring my tank water?

I have explored this issue in great depth and not been able to pinpoint my cause. That is why this thread is titled asking how fast I can drop alkalinity, not why is my alkalinity increasing.

Perhaps you are experiencing the Dunning-Kruger effect with your ability to read a post and actually answer the question being asked rather than spout off how much you know about something I didn’t ask about.

Oh, and you can also tell Dr RHF he’s an idiot for saying there are ways Alkalintiy can increase, especially when tank demand is low enough to not compensate for other natural processes.

Lol. Just trying to prevent you from doing summit really stupid, that’s all. We alll do stupid stuff.

You got a pic of your tank?

 

[AFHokie]

Lol. Just trying to prevent you from doing summit really stupid, that’s all. We alll do stupid stuff.

You got a pic of your tank?

Thanks. I do plenty of stupid stuff.

My wife took this one a few days ago. Not the best but most current FTS I have. The setosa and stylo down in front are mounted now.

 

[Chriokid79]

Tank looks awesome.