Who cares about pH??

[Murphs_Reef]

So watching a bsr live last night, there was a topic on pH and coral growth. Having a level 8.3 promotes a healthy and steady growth for LPS / SPS. 

Personally, I haven't monitored pH for years.  Question is, should I? I'm not sure, maybe. 

Out of interest I have an old API pH test kit (only just in date by 2 months) so decided to check it. It came out at 8.4 so just above what bsr are telling me is good.. not sure how accurate API is for pH but that's a different issue. 

 

Who cares? Do you? Do you measure pH? 

[stevie1493]

8 minutes ago, Murphych said:

Who cares?

I personally have experienced that if I mix SW to the appropriate salinity, pH should naturally be where it's supposed to be. I don't worry about pH.

 

8 minutes ago, Murphych said:

Do you measure pH? 

Unless experiencing a livestock issue I might test for it once a month. It happens I tested it today for the first time in maybe 6 weeks.. 8.0 which has been what my tank has been steady at for 6 months. The tests are so quick and easy.

[Clown79]

I stopped testing ph long ago.

 

Its a parameter that fluctuates throughout the day. 

 

My focal point was Alk. If Alk is good, ph should be as well, they effect eachother.

[mcarroll]

3 hours ago, Murphych said:

So watching a bsr live last night, there was a topic on pH and coral growth. Having a level 8.3 promotes a healthy and steady growth for LPS / SPS. 

Easy for them to say just about whatever they want.

 

How many reefers can you count that have "healthy and steady growth" but without the hogwash?  

 

If that number is more than zero, you can fully discount the info in that video.

 

3 hours ago, Murphych said:

not sure how accurate API is for pH but that's a different issue. 

I would doubt that result, if that helps.  

 

Most homes have CO2 levels that are at least slightly elevated, so pH is at least slightly depressed....usually something like 7.7 or 7.8.  Unless I'm mistaken, your kit doesn't have that kind of resolution though.

 

If you want to watch pH to see what of interest may happen, a live pH monitor is the real ticket.   There are some interesting things to notice, but nothing particularly actionable.   It's very interesting to watch the pH of a fresh bucket of salt being mixed, for example.

 

 

[blasterman]

Yes....pH is very important.

 

Yes.....higher pH levels make SPS grow faster. MUCH faster, and thicker. Montipora in my 20L literally grow twice as thick at a pH of 8 3 to 8 4 vs 8.1. My acans, gobstoppers and and other large zoa colonies puff up to double their size when I run the higher pH level vs normal 8.1 My calcium consumption goes up 50% or more at higher pH levels.

 

The problem is that there's not much most reefers, especially behinners can do about it. You can open a window, or run a fuge full of chaeto in reverse light cycle, but those have limited effect.

 

Another problem is the nightly pH crash tanks have as photosynthesis ends and biology switches to producing CO2 at night. When the lights flip back on during the next day it usually takes hours for all that CO2 produced at night to burn off. My tank runs 8.1 during the day max and dips to 7.6 at night in a room with excellent outdoor ventilation. When the light flips back on in the morning my pH doesn't crawl back up to 8.1 until half the photo period is done. So, I start dosing sodium hydroxide / sodium carbonate early in the morning so when lights kick on my pH is already at 8.3 and hits up to 8.4 by mid day. Massive difference in SPS growth. 

 

Alk levels have little to do with pH problems. 

[Clown79]

2 hours ago, blasterman said:

Yes....pH is very important.

 

Yes.....higher pH levels make SPS grow faster. MUCH faster, and thicker. Montipora in my 20L literally grow twice as thick at a pH of 8 3 to 8 4 vs 8.1. My acans, gobstoppers and and other large zoa colonies puff up to double their size when I run the higher pH level vs normal 8.1 My calcium consumption goes up 50% or more at higher pH levels.

 

The problem is that there's not much most reefers, especially behinners can do about it. You can open a window, or run a fuge full of chaeto in reverse light cycle, but those have limited effect.

 

Another problem is the nightly pH crash tanks have as photosynthesis ends and biology switches to producing CO2 at night. When the lights flip back on during the next day it usually takes hours for all that CO2 produced at night to burn off. My tank runs 8.1 during the day max and dips to 7.6 at night in a room with excellent outdoor ventilation. When the light flips back on in the morning my pH doesn't crawl back up to 8.1 until half the photo period is done. So, I start dosing sodium hydroxide / sodium carbonate early in the morning so when lights kick on my pH is already at 8.3 and hits up to 8.4 by mid day. Massive difference in SPS growth. 

 

Alk levels have little to do with pH problems. 

There is a relationship between alkalinityband ph and their effects on one another.

 

We are seeing the current effects of the increase of co2 in the oceans, which is dropping ph levels and in turn also effecting alkalinity.

https://reefs.com/magazine/chemistry-and-the-aquarium-the-relationship-between-alkalinity-and-ph/

 

[blasterman]

 From the article you linked:

 

From this data it is clear to see the large increase in pH caused by the addition of hydroxide, and also the significant increase when using carbonate. Bicarbonate, on the other hand, shows the expected slight decrease in pH,

 

Which basically means the article is agreeing with me. The most common source of carbonate alk in reef tanks is sodium bicarbonate, aka baking soda., Salt mixes use sodium bicarbonate as their alk component. That fancy bag of salt mix uses nothing but baking soda as it's alk component. That fancy bottle or jug of two part dosing mix you paid for is nothing more than baking soda in water.

 

No salt mix I know uses sodium carbonate as a base alk because a big water change would send pH through the roof. Boron contributes just a fraction of carbonate alkalinity and there's no proof boron anything as a trace element.

 

Calcium Hydroxide, aka kalk raises pH via raising carbonate (alk ) levels along with calcium. The problem is unless you have SPS corals or clams eating that calcium you will end up with high calcium and low alk.

 

Sodium carbonate (baked baking soda aka soda ash) allows you to raise pH and alk but not calcium. It's the best way to go if you dose for alk...which in my opinion serious reefers should because you will have happier and faster growing coral with the pH boost and sodium carbonate is easy to make (baking soda in an oven for 30minutes). Sodium hydroxide is my weapon, but it's not for beginners. 

 

There are no boats driving around the ocean dumping baking soda keeping alk levels stable. Also, the Co2 levels in our tanks is orders magnitude higher than the ocean which may explain why so many beginners end of with dead corals. Short form: just raising alk in your tank wont affect pH, at least not in any significant way.  You CAN use alk dosing via the methods I list to raise pH as a side effect (sodium carbonate or sodium hydroxide)  but this is an artificial solution and not directly related to carbonate saturation levels.  Fill a cup with tank water, add baking soda, and observe how pH doesn't go up. Try it. 

 

All of the high end coral farms I've bought frags from the past few years keep their pH artificially elevated at 8.3 to 8.4.  All of them.  

 

 

[Murphs_Reef]

Very interesting indeed thank you all. 

 

So on Saturday evening I measured my pH at 8.4 yesterday at around the same time if day, it was recorded at 7.8.. now this could be due to using an API kit I had (I use this kit to ball park my daughter's tank, I'm not concerned with pin point on that tank).

But are there other factors that would cause this large swing? Understand that c02 impacts against pH levels, and that running skimmer will help driver it out. Opening windows helps pull fresh air in and all that good stuff. Do I need to sit and freeze at winter with windows open or bake baking soda every other day to ensure pH is correct? I'm still not sure I should care that much?

[mcarroll]

If you test at the same time of day (and your lights are on a regular schedule) that should eliminate most "random" variability....which is from CO2 uptake during photosynthesis.

 

If you test the same sample for pH three times (ie "in triplicate"), do you get more or less identical readings on each test?  Or do they show the same variability you described just now?

 

3 hours ago, Murphych said:

Do I need to sit and freeze at winter with windows open or bake baking soda every other day to ensure pH is correct?

That's not something anyone ever needs to do.  Some folks might choose it, but that's another situation entirely.  👍

[Murphs_Reef]

1 hour ago, mcarroll said:

If you test the same sample for pH three times (ie "in triplicate"), do you get more or less identical readings on each test?  Or do they show the same variability you described just now?

I'll try the triple test  later today so it's in line timing wise with the others. 👍🏼  

Again it's more of a curiosity item for me at the moment as I'm not sure I have any issues to fix?

[mcarroll]

Seems like this might be worth a re-post:  Biological control of aragonite formation in stony corals

 

Aragonite secretion in corals is actually controlled biologically, so it isn't dependent on the surrounding water's pH, per se.

 

Many other more significant factors are at work, such as light level and feeding status.  

 

Mixed up in this seems to be a presumption that less dense skeletons are automatically a problem for the coral vs presuming that it's an adapted response to (e.g.) allow more vegetative spreading when conditions favor it.  Terrestrial plants routinely use this strategy for spreading their DNA...it's not surprising to me to see the same phenomena with corals.

 

(To me, this seems obvious....but isn't something I've seen mentioned in the literature so far...)

 

[mcarroll]

11 hours ago, mcarroll said:

(To me, this seems obvious....but isn't something I've seen mentioned in the literature so far...)

Had a few minutes to dig....here's one article that at least talks about the vegetative mode in a coral we are a little familiar with:

Effect of tropical storms on sexual and asexual reproduction in coral Pocillopora verrucosa subpopulations in the Gulf of California

(PDF Link)

(Google Scholar always seems to like a challenge. 😉)

 

Make sure you click through to read the PDF....it's not that long of a read.

 

BTW, there seems to be a lot of articles out there on solitary corals that propagate by vegetative means...also very similar to the process we know with reef building corals, but the solitary coral names are unfamiliar to us so I just didn't link any.