Low PH with High Calcium and Alkalinity

[fragalicious]

I am about 10 months into a reef tank. I have had some good and bad luck along the lines with corals.

Right now I have branching hammers, multiple mushrooms, pom pom, green star, pipe organ, goni, orange tube, bubble tip, two clowns and some gobies.

For the life of my aquarium mostly, my PH has been low but everything else in good ranges. I have tried multiple test kits and get around the same thing. As of today:

PH: 7.6
Cal: 490
Alk: 8.5
Salinity: 1.024 ( was 1.023 before a water change a few days ago )
Mag: 1600
Nitrite: 0

I just lost two Ducans about 3 days ago to brown jelly after i lost one 3 months ago to it.

I swear today, my mushrooms don't look as good and the hammer doesn't either. The hammer was very full a few days ago and just looks shrunken.

So, my main question is how to get my PH up given the other parameters. I am not sure if I am paranoid with having lost duncans, but i love my hammers and do not want them to die.

 

[fragalicious]

Here is the hammer I am worried about. All three main heads were pretty full 2 days ago.

 

[dvgyfresh]

Mg is a little high, is there enough flow? Surface agitation ? Any windows near tank ect, these all can affect ph

 

[fragalicious]

Pretty good flow throughout the tank. I've been moving it around here and there to try and see what is right. Not near windows. I did recently move a powerhead to reduce surface agitation, but the PH has been low well before that

 

[dvgyfresh]

Pretty good flow throughout the tank. I've been moving it around here and there to try and see what is right. Not near windows. I did recently move a powerhead to reduce surface agitation, but the PH has been low well before that

Because it’s been stable at the lower value I think it may be low concentration of oxygen in the home , you can run a air line through skimmer to help or dose kalk by drip just be careful because it also affects calc and alk

 

[mdb_talon]

For starters I would see what your PH range is throughout the day over the course of a few days. In all likelihood it is not a stable 7.6. Does it bounce from 7.6 to 7.8 for example or maybe 7.4 to 7.6? In other words is that 7.6 somewhere at the high point, low point, or middle of the daily range it likely has? The answer gives an indication to just how low your PH is and the urgency in raising it.

I am a firm believer in generally not chasing a PH number, but agree 7.6 seems low. I would search R2R for aeration tests you can do to see if high CO2 is part of the problem. Do it outside to get fresh air. If you find aerated saltwater outside causes the PH to significantly rise there are steps you can take to address that (co2 scrubber, outside airline to skimmer, etc).

I also could be wrong, but I dont think a 7.6 PH is causing brown jelly disease other than possibly stressed corals are more susceptible to disease.

 

[William Morris]

If you run a skimmer you can add a diy Co2 scrubber to the airline filled with soda lime.
Since I installed this on my 32G Biocube my PH at the peak of the cycle has been a steady 8.1 - 8.2.
It has made a big difference.
If your interested I can give you the details.

 

[Hans-Werner]

In my opinion the pH is not so important but I think high alkalinity can actually lower pH. The mechanism by which it does is oversaturation and precipitation.

With high alkalinity the water is more oversaturated with aragonite (calcium carbonate) and closer to preciptation. The pH lowering effect may be caused by two mechanisms:

- When pH starts to increase during the day by the photosynthetic activity of corals and algae the formation of precipitates sets the upper limit to pH increase because the formation of precipitates depresses pH.

- Similar but in the calcification process. The calcification process starts at lower pH when water is more oversaturated and the pH increase may be reduced.

I am not sure whether I already have checked whether my theory is correct but I will do it this week. In theory it works, I am sure.

Phosphate inhibits the formation of calcium carbonate precipitates and in this way makes higher pH increase possible. In fact there is at least the tendency of low phosphate tanks to also have lower pH.

Do you know the phosphate concentration in your tank? Maybe the mortalities and the bad look may be attributed to low phosphate concentration?

 

[Dr. Dendrostein]

I am about 10 months into a reef tank. I have had some good and bad luck along the lines with corals.

Right now I have branching hammers, multiple mushrooms, pom pom, green star, pipe organ, goni, orange tube, bubble tip, two clowns and some gobies.

For the life of my aquarium mostly, my PH has been low but everything else in good ranges. I have tried multiple test kits and get around the same thing. As of today:

PH: 7.6
Cal: 490
Alk: 8.5
Salinity: 1.024 ( was 1.023 before a water change a few days ago )
Mag: 1600
Nitrite: 0

I just lost two Ducans about 3 days ago to brown jelly after i lost one 3 months ago to it.

I swear today, my mushrooms don't look as good and the hammer doesn't either. The hammer was very full a few days ago and just looks shrunken.

So, my main question is how to get my PH up given the other parameters. I am not sure if I am paranoid with having lost duncans, but i love my hammers and do not want them to die.

Set up a reactor, gently tumble argonite sand(like gfo), do some water changes slowly, don't rush.You'll be around 8.0 ph . Unfortunately you will loose some corals. We all been there. Bummer You'll be around 8.0 ph maybe higher

 

[redeyejedi]

Well... i think the coral issues prob isnt PH. The most important parameters for lps is P04. You need to check how high yours is.

 

[redeyejedi]

Or looking at the pic could just be Aiptasia bugging stuff.

 

[Randy Holmes-Farley Verified Community Expert]

Mg is a little high, is there enough flow? Surface agitation ? Any windows near tank ect, these all can affect ph

FWIW, magnesium does not impact pH at all.

 

[Randy Holmes-Farley Verified Community Expert]

In my opinion the pH is not so important but I think high alkalinity can actually lower pH. The mechanism by which it does is oversaturation and precipitation.

With high alkalinity the water is more oversaturated with aragonite (calcium carbonate) and closer to preciptation. The pH lowering effect may be caused by two mechanisms:

- When pH starts to increase during the day by the photosynthetic activity of corals and algae the formation of precipitates sets the upper limit to pH increase because the formation of precipitates depresses pH.

- Similar but in the calcification process. The calcification process starts at lower pH when water is more oversaturated and the pH increase may be reduced.

I am not sure whether I already have checked whether my theory is correct but I will do it this week. In theory it works, I am sure.

Phosphate inhibits the formation of calcium carbonate precipitates and in this way makes higher pH increase possible. In fact there is at least the tendency of low phosphate tanks to also have lower pH.

Do you know the phosphate concentration in your tank? Maybe the mortalities and the bad look may be attributed to low phosphate concentration?

IMO, that makes no chemical sense.

High alkalinity immediately leads to higher pH. At the same CO2 level, pH MUST be higher at higher alkalinity. It is a simple mathematical relationship.

It is true that formation of calcium carbonate tends to lower pH by removing carbonate (lowering alkalinity). By Le Chatlier's Principle, removing carbonate lowers pH by causing a bicarbonate to split into H+ and CO3-- to partly replace the lost carbonate.

However, that process is not done by itself. Reefers also supplement back the alkalinity.

If that supplementing is done with carbonate, then the whole process of supplementation to CaCO3 formation has zero net effect on pH. Carbonate in, carbonate out. No pH effect.

If the reefer uses hydroxide to boost alk, then the net effect is a pH rise: hydroxide in, combine with CO2, raise ph, carbonate out.

If the reefer uses bicarbonate to boost alk, then the net effect is a pH drop: bicarbonate in, , lower pH, carbonate out.

 

[LeftyReefer]

If you run a skimmer you can add a diy Co2 scrubber to the airline filled with soda lime.
Since I installed this on my 32G Biocube my PH at the peak of the cycle has been a steady 8.1 - 8.2.
It has made a big difference.
If your interested I can give you the details.

Can you send me details on your DIY scrubber? I have low pH in my basement tank that doesn't get enough fresh O2. This scrubber might help until I can get an outside airline installed as a more permanent fix. thanks!

 

[Randy Holmes-Farley Verified Community Expert]

I am about 10 months into a reef tank. I have had some good and bad luck along the lines with corals.

Right now I have branching hammers, multiple mushrooms, pom pom, green star, pipe organ, goni, orange tube, bubble tip, two clowns and some gobies.

For the life of my aquarium mostly, my PH has been low but everything else in good ranges. I have tried multiple test kits and get around the same thing. As of today:

PH: 7.6
Cal: 490
Alk: 8.5
Salinity: 1.024 ( was 1.023 before a water change a few days ago )
Mag: 1600
Nitrite: 0

I just lost two Ducans about 3 days ago to brown jelly after i lost one 3 months ago to it.

I swear today, my mushrooms don't look as good and the hammer doesn't either. The hammer was very full a few days ago and just looks shrunken.

So, my main question is how to get my PH up given the other parameters. I am not sure if I am paranoid with having lost duncans, but i love my hammers and do not want them to die.

I would not be sure the pH is accurate, but if so, it is a substantial long term concern because coral skeletons can slowly dissolve under those posted conditions.

I also do not know if the problems reported by you about your corals is pH related and not something else, but I would look to raise the pH.

The first thing to do is determine if the pH is accurate. How did you measure it?

Assuming the daily pH low is actually 7.6 or lower, then I'd look to raise it by one of the methods detailed here:

pH And The Reef Aquarium
http://www.reefedition.com/ph-and-the-reef-aquarium/

 

[Randy Holmes-Farley Verified Community Expert]

Can you send me details on your DIY scrubber? I have low pH in my basement tank that doesn't get enough fresh O2. This scrubber might help until I can get an outside airline installed as a more permanent fix. thanks!

FWIW, scrubbers do not appreciably increase O2, and O2 has no effect on pH. They decrease CO2. It is always CO2 you want to focus on.

Many people mistakenly assume they always move in opposite directions, but that is not true. Reef tanks can easily have both higher than normal (daytime peak, usually, from high room CO2 and high O2 in the water from photosynthesis)) or both low (e.g., a tank using hydroxide for alkalinity at night), or one up and one down.

 

[LeftyReefer]

FWIW, scrubbers do not appreciably increase O2, and O2 has no effect on pH. They decrease CO2. It is always CO2 you want to focus on.

Many people mistakenly assume they always move in opposite directions, but that is not true. Reef tanks can easily have both higher than normal (daytime peak, usually, from high room CO2 and high O2 in the water from photosynthesis)) or both low (e.g., a tank using hydroxide for alkalinity at night), or one up and one down.

Right on. My basement has higher levels of CO2 compared to the upper levels of the house. My plan is to run an outside airline to my skimmer to supply it with outside (lower CO2) air rather than having it pull the air from my basement. Unfortunately, I'm probably going to have to wait until spring before tackling that project. So in the meantime, I was hoping one of these DIY scrubbers might work.

 

[Hans-Werner]

IMO, that makes no chemical sense.

Maybe, except that it is not primarily a chemical system but a biological system, where processes take place that remove or release CO2 for example.

That makes things a bit more ... complex With the carbonate in, carbonate out "equation", no CO2 is available to corals and coralline algae.

And there is the CO2 equilibrium with air. If the relationship would be really simple I think there should be more similarity between this alkalinity map and this pH map.

However I cannot respond with a really clever explanation. I guess, only measuring and titrating will help.

But the pH is not so important anyway.

 

[William Morris]

Can you send me details on your DIY scrubber? I have low pH in my basement tank that doesn't get enough fresh O2. This scrubber might help until I can get an outside airline installed as a more permanent fix. thanks!

Article where I got the idea from.
I used Jorvet Soda Lime (Amazon) because the reviews on the BRS Soda Lime are not very good right now.
Salter Labs water trap
Not sure what size your tank is - you may have to use a larger version of this idea.

 

[Randy Holmes-Farley Verified Community Expert]

Maybe, except that it is not primarily a chemical system but a biological system, where processes take place that remove or release CO2 for example.

That makes things a bit more ... complex With the carbonate in, carbonate out "equation", no CO2 is available to corals and coralline algae.

And there is the CO2 equilibrium with air. If the relationship would be really simple I think there should be more similarity between this alkalinity map and this pH map.

However I cannot respond with a really clever explanation. I guess, only measuring and titrating will help.

But the pH is not so important anyway.

The three things are tied exactly mathematically: CO2 levels, alkalinity, and pH. Higher alkalinity at fixed CO2 means higher pH.

Chemistry And The Aquarium: The Relationship Between Alkalinity And pH

Randy answers many questions in this complex relationship.

reefs.com

2. Ac = (K1KHPCO2 / [H+]) + 2(K1K2KHPCO2 / [H+]2)

Of course, if an organism releases or consumes CO2, the pH will change at fixed alkalinity. .

But I do not believe there is any plausible reason to suggest that higher alkalinity leads to lower pH, unless one is supplying alkalinity back to the system in a way that itself lowers pH.