??? about alk and ph
- Thread starter teddyb
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sedor
New member
No teddy your ph will fluctuate due to carbon gas exchange. During the day when the lights are on it will be up, and when lights are off...down. Its normal for a small swing like that. Alkalinity buffers will spike the ph when they are added to the tank, but they don't have any part in affecting the ph long term.
Some choose to use a kalk reactor in conjunction with a controller and ph probe so they can dose kalk when the ph drops below a certain level, but again this is the same concept as an alk buffer, its simply spiking the ph for a short period of time, it will inevitably do its thing.
Now that this response is turning into a novel I might as well add that I personally think to many people are way to concerned about ph. In a normal environment it shouldn't be to much to worry about. If your house has unusual levels of carbon dioxide thats when ph can start to become a problem. If you run an open top, a skimmer and have decent surface agitation you shouldn't ever really have to worry.
Some choose to use a kalk reactor in conjunction with a controller and ph probe so they can dose kalk when the ph drops below a certain level, but again this is the same concept as an alk buffer, its simply spiking the ph for a short period of time, it will inevitably do its thing.
Now that this response is turning into a novel I might as well add that I personally think to many people are way to concerned about ph. In a normal environment it shouldn't be to much to worry about. If your house has unusual levels of carbon dioxide thats when ph can start to become a problem. If you run an open top, a skimmer and have decent surface agitation you shouldn't ever really have to worry.
Thanks Ryan, I don't mind a long response. The reason I was asking is because a buddy of mine has a really nice tank with a lot of sps in it and his corals grow but his back wall only has a few spots of coralline growth. He says that all he does is water changes and makes sure his pH stays high. He says that if your pH stays high, the water can get all the calcium it needs provided you have enough live rock.
I dose calcium and my back wall is covered with coralline. I hate it because some coralline overgrew a tiny piece (microscopic really) of chalice that I had.
I dose calcium and my back wall is covered with coralline. I hate it because some coralline overgrew a tiny piece (microscopic really) of chalice that I had.
High pH help corals deposit calcium carbonate, but live rock won't add any calcium to the water column. Water changes will, but most tanks require supplementation to keep up high growth rates.
Lower pH actually helps dissolve calcium carbonate and supply both calcium and alkalinity to the water column. That's how calcium reactors work. It's possible to use live rock as a reactor media, although the cost and possible contaminants can be an issue.
Lower pH actually helps dissolve calcium carbonate and supply both calcium and alkalinity to the water column. That's how calcium reactors work. It's possible to use live rock as a reactor media, although the cost and possible contaminants can be an issue.
Buffers not only spike ph short term;they add alkalinity.Using buffers to make short term adjustments to ph is not a good strategy.
Maintaining a good range of alkalinity (7 to11 dkh) consistently will help minimize ph swings related to the normal rise in CO2 when photosynthesis stops for the day.The H+ generated by by carbonic acid from CO2 can be taken up by carbonate to form bicarbonate in response to ph changes lessening the drop in ph when the lights go off.. You can maintain alkalinity with water changes , commercial buffers , baking soda or by dripping kalkwasser which is an alkalinity and calcium supplement.
An opposite photo period refugium with macroalgae( chaetomorpha) will help as well.It will also provide oxygen when the photosynthetic organisms in the tank stop doing so.
Water changes do add calcium and alkalinity from the salt mix. The process also removes acidic wastes from the system. In some systems calcium, magnesium and alkalinity can be maintained with frequent water changes particularly if a slat with relatively high alkalinity,magnesium and calcium content is used. Coraline likes magnesium,calcium and alkalinity. So perhaps your buddy should check these. In my experience, coraline grows less in very bright light.
Maintaining a good range of alkalinity (7 to11 dkh) consistently will help minimize ph swings related to the normal rise in CO2 when photosynthesis stops for the day.The H+ generated by by carbonic acid from CO2 can be taken up by carbonate to form bicarbonate in response to ph changes lessening the drop in ph when the lights go off.. You can maintain alkalinity with water changes , commercial buffers , baking soda or by dripping kalkwasser which is an alkalinity and calcium supplement.
An opposite photo period refugium with macroalgae( chaetomorpha) will help as well.It will also provide oxygen when the photosynthetic organisms in the tank stop doing so.
Water changes do add calcium and alkalinity from the salt mix. The process also removes acidic wastes from the system. In some systems calcium, magnesium and alkalinity can be maintained with frequent water changes particularly if a slat with relatively high alkalinity,magnesium and calcium content is used. Coraline likes magnesium,calcium and alkalinity. So perhaps your buddy should check these. In my experience, coraline grows less in very bright light.
stooges3tx
New member
+1 to what Ryan said.
I also believe there is a high emphasis on PH. If you maintain your Alk and agitate the surface your PH will not vary that much and will be able to hold steady where you want it.
http://reefkeeping.com/issues/2004-05/rhf/index.php
Not sure if you know him but Mr. Holmes-Farley is a good good man.
I also believe there is a high emphasis on PH. If you maintain your Alk and agitate the surface your PH will not vary that much and will be able to hold steady where you want it.
http://reefkeeping.com/issues/2004-05/rhf/index.php
Not sure if you know him but Mr. Holmes-Farley is a good good man.
Very true in that Mr. Holmes-Farley has some good info, but as with all info. it is best to incorporate it into other bits of instruction/knowledge and not take just one viewpoint as gospel. There is some good info in that article, but to take it as the absolute would not be wise.<a href=showthread.php?s=&postid=15617396#post15617396 target=_blank>Originally posted</a> by stooges3tx
+1 to what Ryan said.
I also believe there is a high emphasis on PH. If you maintain your Alk and agitate the surface your PH will not vary that much and will be able to hold steady where you want it.
http://reefkeeping.com/issues/2004-05/rhf/index.php
Not sure if you know him but Mr. Holmes-Farley is a good good man.
HighlandReefer
Team RC
Re: ??? about alk and ph
Test kits for pH are not the most accurate and trying to judge the colors can be difficult. I would save up for a dual calibrated pH meter.
Many hobbyists have come to this forum who are using properly calibrated pH meters and have low end pH levels that drop below the recommended minimum level of 7.8. The reason why Dr. Randy Holmes-Farley recommends a minimum pH level of 7.8 is that the calcium carbonate that forms the backbone of coral will begin to dissolve at a pH level below 7.8. As the pH drops lower and lower, the calcium carbonate will dissolve faster, like you find in calcium reactors. This is scientific fact demonstrated over and over again. Hence the recommendation by Dr Holmes-Farley.
It appears that higher alkalinity levels will help offset the dissolving of the calcium carbonate at lower than 7.8 pH levels. I have not seen any scientific data about this subject. Higher alkalinity levels will buffer the pH swings and help reduce the amount of change from day to night, but even at higher alk levels, 11-12 dKH, your pH can drop below 7.8 if you have high CO2 levels in your home.
I have found, if you use kalk water to supplement your alk. and calcium, this keeps your pH low level above 7.8, especially if your alk. level is between 10-12 dKH.
Regarding low pH due to high CO2 levels in your home, which is very common, Randy goes into more details as to why this occurs in this article:
Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm
Test kits for pH are not the most accurate and trying to judge the colors can be difficult. I would save up for a dual calibrated pH meter.
Many hobbyists have come to this forum who are using properly calibrated pH meters and have low end pH levels that drop below the recommended minimum level of 7.8. The reason why Dr. Randy Holmes-Farley recommends a minimum pH level of 7.8 is that the calcium carbonate that forms the backbone of coral will begin to dissolve at a pH level below 7.8. As the pH drops lower and lower, the calcium carbonate will dissolve faster, like you find in calcium reactors. This is scientific fact demonstrated over and over again. Hence the recommendation by Dr Holmes-Farley.
It appears that higher alkalinity levels will help offset the dissolving of the calcium carbonate at lower than 7.8 pH levels. I have not seen any scientific data about this subject. Higher alkalinity levels will buffer the pH swings and help reduce the amount of change from day to night, but even at higher alk levels, 11-12 dKH, your pH can drop below 7.8 if you have high CO2 levels in your home.
I have found, if you use kalk water to supplement your alk. and calcium, this keeps your pH low level above 7.8, especially if your alk. level is between 10-12 dKH.
Regarding low pH due to high CO2 levels in your home, which is very common, Randy goes into more details as to why this occurs in this article:
Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm
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stooges3tx
New member
Of course you don't take anyone thing as gospel but if the man makes logical sense and proves time and again through scientific knowledge to know what he is talking about you can probably take his advice.
Finsky
New member
My alkilnity tends to be on the high side compared to my ph 8.11, calcium 500 ppm. After a a second 10% water change this week and a Seachem Marine Buffer dose to raise the ph from 7.8, my alkilinity is around 14 dkh?
How high of an alkilinity level is acceptable?
My fish and corals seem to be healthy; including a Regal Angelfish and three goiniporas.
How high of an alkilinity level is acceptable?
My fish and corals seem to be healthy; including a Regal Angelfish and three goiniporas.
HighlandReefer
Team RC
At alkalinity levels higher than 12 dKH, you will get more calcium carbonate precipitate out of solution in your tank. This means build-up on your glass and equipment which can be hard to clean off.
Studies I have read indicate that some sps coral will grow faster as the alk. level climbs up to about 22 or so dKH where they stopped the study.
Randy recommends an alkalinity range between 7-11 dKH, which takes in a lot of factors going on in tank water.
Using buffers to keep your pH up, end up causing high alk. levels as you have experienced. Using kalk water (lime water) in place of two-part is a better way of maintaining a higher pH IMHO. When you dose kalk water or two-part, you dose them to maintain alkalinity and not pH. Many buffers have other chemicals in them that will put your tank water parameters out of balance. I would not use the buffers for that reason and stick with the two-part (baked baking soda) or use kalk water.
Finsky
New member
Thank you HighlandReefer:
I used to use baking soda in my freshwater tanks and now I have been wondering whether it can be used in a reef tank.
Will baking soda just raise PH and not alkilinity and alkilinity will need to be raised by kalk water?
I think I just repeated what you said, I just wanted to make sure.
I used to use baking soda in my freshwater tanks and now I have been wondering whether it can be used in a reef tank.
Will baking soda just raise PH and not alkilinity and alkilinity will need to be raised by kalk water?
I think I just repeated what you said, I just wanted to make sure.
HighlandReefer
Team RC
Baking soda will not raise your pH. What you need to do is bake the baking soda for about an hour at 450 degrees spread out on a cookie sheet in a thin layer of 1" or less. This will turn your baking soda into what is called washing soda or soda ash, which will raise your pH. Both will increase your alkalinity.
You can use the Reef Chemistry Calculator to determine how much you need to add. You have to be careful of overdoses when using baked baking soda, as it will increase your pH higher then you want if overdosed.
Reef chemicals calculator
http://home.comcast.net/~jdieck1/chem_calc3.html
You can use the Reef Chemistry Calculator to determine how much you need to add. You have to be careful of overdoses when using baked baking soda, as it will increase your pH higher then you want if overdosed.
Reef chemicals calculator
http://home.comcast.net/~jdieck1/chem_calc3.html
The Marine Buffer product is designed for fish-only systems, and shouldn't be used in tanks with a lot of stony corals, or where coralline algae growth is desired. It contains a lot of borate. I'd probably do an extra water change or two, and switch to another product.
All of the pH buffer products add alkalinity, by definition. Borate happens to be fairly effective at keeping the pH a bit higher than carbonate alkalinity, but it can't be used by stony corals for their skeletons.
All of the pH buffer products add alkalinity, by definition. Borate happens to be fairly effective at keeping the pH a bit higher than carbonate alkalinity, but it can't be used by stony corals for their skeletons.
stooges3tx
New member
I have just overcome the issue of low Alk in my tank. I never tested my PH through all of this because every time I have ever tested my PH it was within acceptable ranges.
I had Ca ~ 500ppm and had to dose Alk alone to keep it at 8dkh. This went on for awhile. Then I started testing my Mg. Found it was low and dosed it correctly. Almost instantly my water cleared up and Ca went up higher. I still had the issue with the Alk until after about a week. It seems that I dumped so much 2 part in equally that the Ca was not able to be used by the tank and was "calcifiying" so even my test kit could not read the proper levels that were actually locked in the water. I used the buffer to stabalize Alk while maintaining Mg and low and behold.....
My Ca is at 400ppm dkh 9 and Mg at 1300ppm. All stable with a fraction of what I used to dose previously. Point is check your Mg then balance/stabalize your Ca Alk and your PH should be fine. Alk allows your tank to handle the other factors that may affect your PH fluctuations. Maintaining Alk will allow PH to stay relatively stable if you have the surface agitation and everything else stated in this thread.
I had Ca ~ 500ppm and had to dose Alk alone to keep it at 8dkh. This went on for awhile. Then I started testing my Mg. Found it was low and dosed it correctly. Almost instantly my water cleared up and Ca went up higher. I still had the issue with the Alk until after about a week. It seems that I dumped so much 2 part in equally that the Ca was not able to be used by the tank and was "calcifiying" so even my test kit could not read the proper levels that were actually locked in the water. I used the buffer to stabalize Alk while maintaining Mg and low and behold.....
My Ca is at 400ppm dkh 9 and Mg at 1300ppm. All stable with a fraction of what I used to dose previously. Point is check your Mg then balance/stabalize your Ca Alk and your PH should be fine. Alk allows your tank to handle the other factors that may affect your PH fluctuations. Maintaining Alk will allow PH to stay relatively stable if you have the surface agitation and everything else stated in this thread.
