Potassium Hydroxide Dosing??

[ShoreReefer]

@Randy Holmes-Farley do you see any issues with Chris's method of dosing saturated kalk and using your ph probe to control the amount is dosed throughout the day? A local reefer/coral vendor recently said that he's been using this method for about a year and his ph is consistently between 8.2 and 8.3 day and night and has seen tremendous coral growth. Since i can use the APEX with the DOS and Trident to control everything including the testing, I was thinking of trying this method of dosing saturated kalk as well.

 

[EugeneVan]

I called out how bad the info was in the comments, and I got blasted for not "respecting him because he touches more corals in a week than I will in my lifetime" as if touching corals garners respect lol you can easily have a successful reef and have no idea WHY

Yes, I'm the bad guy for telling you the guy has very little good advice in this video. lol

He forget the last part, he also kill more coral than anybody in their lifetime

 

[EugeneVan]

No one's questioning Chris's ability to keep Coral. That's not the issue here.
In fact, your post is perfect evidence of how people will believe other people on the internet based on non-relevant experience and expertise. Just because somebody is good at something, doesn't make them an expert in all related material and areas. Here he is simply spreading misinformation in an area that is outside of his expertise.

I think his Marine scientist and physicist friends must have a PHD degree either from Facebook or Google university

 

[Randy Holmes-Farley]

@Randy Holmes-Farley do you see any issues with Chris's method of dosing saturated kalk and using your ph probe to control the amount is dosed throughout the day? A local reefer/coral vendor recently said that he's been using this method for about a year and his ph is consistently between 8.2 and 8.3 day and night and has seen tremendous coral growth. Since i can use the APEX with the DOS and Trident to control everything including the testing, I was thinking of trying this method of dosing saturated kalk as well.

The implications are unstable alkalinity, possibly also rising to excessive levels if not limited somehow.

Many reefers seem to think that stable alk leads their systems to better success than less stable alk. But there is very limited actual experimentation in this regard, with proper controls and such. Consequently I’m wary to give a strong opinion on the effects.

 

[Randy Holmes-Farley]

FWIW, experimentation on an individual system is the only way to know what pH is attained by dosing hydroxide or carbonate or bicarbonate for all alk needs, but it does not seem unduly complicated to me to dose hydroxide when you want alkalinity and a pH boost, and bicarbonate when you want alkalinity and no pH boost.

An alk controller and a pH controller can likely be rigged up to to this automatically.

 

[Shooter6]

The implications are unstable alkalinity, possibly also rising to excessive levels if not limited somehow.

Many reefers seem to think that stable alk leads their systems to better success than less stable alk. But there is very limited actual experimentation in this regard, with proper controls and such. Consequently I’m wary to give a strong opinion on the effects.

I believe he has limitations in place via the ph probe and the Trident he runs. I have no experience with the apex and Trident ( don't trust the single failure point apex causes) but it has the ability to shut down dosing if alk fluctuations are tested right? He uses calcium reactors as well so kalk is not a single source of alkalinity and calcium.

 

[brmc1985]

I believe he has limitations in place via the ph probe and the Trident he runs. I have no experience with the apex and Trident ( don't trust the single failure point apex causes) but it has the ability to shut down dosing if alk fluctuations are tested right? He uses calcium reactors as well so kalk is not a single source of alkalinity and calcium.

Correct. He says his main source of alk and calc is Kalk and supplements with lots of other things that he doesn’t specify

 

[Shooter6]

Correct. He says his main source of alk and calc is Kalk and supplements with lots of other things that he doesn’t specify

I know one of the vids with him he said calcium reactor is the main source of maintaining his parameters then he added kalk along with the potassium hydroxide to save money on maintaining the numbers. After adding them he saw the benefits of increased ph so that became an important parameter for him to maintain. This is what lead to his current dosing regimen. As I understand it the calcium reactor and potassium hydroxide maintain the bulk of dosing during the day. Then shortly after the lights go out and ph starts to drop the kalkwasser dosing comes online and maintains the ph while dosing the calcium and alkalinity. During this time the co2 to the calcium reactor is turned off via apex/ Trident therefore no fluctuations or minimal fluctuations to the alkalinity/calcium.

I dont know if the potassium hydroxide also is turned off during these hrs or not. Also the potassium hydroxide only raises alk? Not calcium? If so I assume this could be where he's seeing the alk increase but calcium decrease mentioned earlier??

 

[Shooter6]

Correct. He says his main source of alk and calc is Kalk and supplements with lots of other things that he doesn’t specify

In the end I believe his dosing is highly involved with apex/trident controlling many points that could fail. It may work wonders on his farm systems but isn't as possible to scale down to average size systems.

 

[jhuntstl]

IIRC his calcium reactor only turns on when his alk hits 8.4(based on trident). He mentioned at one point his CA reactor not running for months.

 

[Shooter6]

IIRC his calcium reactor only turns on when his alk hits 8.4(based on trident). He mentioned at one point his CA reactor not running for months.

Yes, that months long period happened when he started the potassium hydroxide dosing. According to him, initially he had a huge increase in calcium, and he hypothesized it was excess calcium leaching back out of the rock,sand ect. But then calcium started to drop again so the calcium reactor started again but at a far lower amount.
I believe this is the video where he talks about the calcium reactors.

 

[Randy Holmes-Farley]

FYI, I got an email response from Chris at ACI. He seems to have some misunderstanding of what I have said and think (not sure if he even read my whole email), and I asked for a clarification of whether he stands by his comment that kalkwasser is not balanced because it contains one calcium and two hydroxides.

Apparently, ACI is not going to respond to my email asking if they stand by what they listed that is shown earlier in this thread. Hopefully they have learned it was erroneous.

 

[Randy Holmes-Farley]

I believe he has limitations in place via the ph probe and the Trident he runs. I have no experience with the apex and Trident ( don't trust the single failure point apex causes) but it has the ability to shut down dosing if alk fluctuations are tested right? He uses calcium reactors as well so kalk is not a single source of alkalinity and calcium.

I think he is raising pH with a system like that, but is clearly not solving a significant low pH problem this way (IMO).

For many people, pH 8.1 is not attained by adding all alkalinity needed as hydroxide of any form (such as kalkwasser).

Thus, if the goal is pH 8.2 or higher, then in some systems, the method with either fail to attain pH 8.2, or it will boost alkalinity beyond the target.

In a coral farm, the demand may be so high and CO2 low enough that this is not an issue.

Extrapolating that to many home reefers obviously fails, or else kalkwasser and hydroxide would be a panacea for low pH problems. It is not, and it particularly is not when the alk demand is not especially high.

 

[Shooter6]

I think he is raising pH with a system like that, but is clearly not solving a significant low pH problem this way (IMO).

For many people, pH 8.1 is not attained by adding all alkalinity needed as hydroxide of any form (such as kalkwasser).

Thus, if the goal is pH 8.2 or higher, then in some systems, the method with either fail to attain pH 8.2, or it will boost alkalinity beyond the target.

In a coral farm, the demand may be so high and CO2 low enough that this is not an issue.

Extrapolating that to many home reefers obviously fails, or else kalkwasser and hydroxide would be a panacea for low pH problems. It is not, and it particularly is not when the alk demand is not especially high.

The current push of kalkwasser seems to center around the ph though instead of the ease of use.

So many people used to use it in the 80s- 90s that I was shocked if fell out of favor. Fat to many people followed the trend to calcium reactors when kalk would have easily handled their reefs needs. Then it went back and forth between 3 part and calcium reactors. Only recently has kalkwasser returned to the foreground.

 

[Reefahholic]

It is so sad (IMO) that this is getting such publicity.

There is zero reason to use potassium hydroxide.

Food and other high grades of sodium hydroxide are better choices for a high pH alkalinity supplement, without concerns about excessive potassium.

If you need potassium, using cheap food grade potassium chloride will allow far better control than to try to tie alkalinity dosing and potassium supplementing together.

Not to mention the pH of Kalk is already 12.4! Great stuff IMO. Should give most home aquarists all the pH boost they need.

 

[Shooter6]

Not to mention the pH of Kalk is already 12.4! Great stuff IMO. Should give most home aquarists all the pH boost they need.

Yes , he is not advocating normal home aquarist to use the potassium hydroxide. Actually says most should not. That being said there are the sub group home reefers with large systems or high demand systems that the potassium hydroxide may be beneficial. When you get into the 600g plus systems, dosing anything can become pricey, and the potassium hydroxide may be what kalk is to smaller systems. ( a cheap way to boost alkalinity) from his explanation it sounds like he's dosing less then 1000ml a day of super diluted potassium hydroxide.

 

[Randy Holmes-Farley]

Yes , he is not advocating normal home aquarist to use the potassium hydroxide. Actually says most should not. That being said there are the sub group home reefers with large systems or high demand systems that the potassium hydroxide may be beneficial. When you get into the 600g plus systems, dosing anything can become pricey, and the potassium hydroxide may be what kalk is to smaller systems. ( a cheap way to boost alkalinity) from his explanation it sounds like he's dosing less then 1000ml a day of super diluted potassium hydroxide.

I don’t know of any situation where potassium hydroxide is desirable. If you want hydroxide, use calcium or sodium. Potassium hydroxide will boost potassium every day until it is way higher than NSW.

If you want potassium, dose potassium chloride.

Tying the two together is, IMO, like trying to use a tool that is a combination of a hammer and a saw, and is likely not optimal for making a table.

 

[Shooter6]

I don’t know of any situation where potassium hydroxide is desirable. If you want hydroxide, use calcium or sodium. Potassium hydroxide will boost potassium every day until it is way higher than NSW.

If you want potassium, dose potassium chloride.

Tying the two together is, IMO, like trying to use a tool that is a combination of a hammer and a saw, and is likely not optimal for making a table.

Problem with sodium hydroxide is the increase of sodium having to be delt with in large consumption systems. Calcium reactors and kalkwasser have the benefit of not raising salinity but Calcium reactors have the ph suppression and additional cost of being large enough to keep up. Kalk having evaporation level ceiling. The miniscule amount he doses of the potassium hydroxide may not increase the potassium level above what his system consumes. I know in the latest video I saw he was in on melves reef channel, he said he does weekly icp test. If potassium overdose was a problem I'd assume he would see it occurring via icp test?

 

[Randy Holmes-Farley]

Problem with sodium hydroxide is the increase of sodium having to be delt with in large consumption systems. Calcium reactors and kalkwasser have the benefit of not raising salinity but Calcium reactors have the ph suppression and additional cost of being large enough to keep up. Kalk having evaporation level ceiling. The miniscule amount he doses of the potassium hydroxide may not increase the potassium level above what his system consumes. I know in the latest video I saw he was in on melves reef channel, he said he does weekly icp test. If potassium overdose was a problem I'd assume he would see it occurring via icp test?

I really need to respond strongly here. No offense intended to you, but IMO is is a serious mistake to dose potassium hydroxide to boost pH long term, and I do not want anyone going away from this thread without at least hearing me say that, even if they still want to try it. It is a seriously flawed method that risks rapidly escalating potassium, and there are far better methods that do not risk that concern..

I really do not understand how potassium ever got fingered for this use, unless the "inventor" was just unaware of better options (sodium hydroxide).

Yes, calcium hydroxide is almost balanced and is a good choice that I used for 20 years.

Sodium hydroxide used with a DIY Balling type two part is also balanced and is also a very good choice. Way, way better than potassium. Even without the Balling part C, it is better than potassium.

Potassium hydroxide at levels sufficient to significantly move the pH needle IS NOT EVER appropriate long term, and there's no way to make it OK (IMO). I do not believe coral uptake can match the amount needed. And if you dose much less, you get a pH effect too small to be useful.

Why do you suppose NO commercial reef alk supplements are potassium bicarbonate or potassium carbonate? Same exact problem that everyone already understands. But somehow if we go to hydroxide as the alk additive, potassium becomes OK? Not.

let's look:

Let's suppose we add 1 dKH per day for a year. That's 0.36 meq/L per day or 130 milliequivalents per L per year.

If we add that as NaOH or KOH, then we must be adding 130 meq/L per year

How much Na+ (mw = 23 mg/milliequivalent) and K+ (mw = 39 mg/milliequivalent) is that?

130 meq/L is

Na+ ---> 23 x 130 = 2,990 mg/L
K+ ---> 39 x 130 = 5,070 mg/L

So potassium has risen from 400 mg/l to 5,470 mg/L a 1,468% increase.
Sodium has risen from 10,800 to 13,790 mg/L a 26% increase

Thus, the rise in potassium is HUGE and the rise in sodium is not. Of course, both are impacted and reduced similarly by salinity corrections and water changes, but the overall effect is that the potassium rise can still be very large (because more mass is added and the starting concentration is far lower) and the sodium rise is not.

 

[OfficeReefer]

Thank you for the insight. I as well thought the usual method was using sodium hydroxide and didn't think it was wise to endlessly raise your potassium through the addition of KOH to fill your Alk / PH needs!

This is exactly why I posted the video for discussion, I knew there were better options and you were the guy who could explain why.

Thanks for everything you do.

Just so you know, this isn't even what the TFP forum advises for pools... for the same reasons. I don't think people realize what they are putting in their tank sometimes.