PH, KH and Alkanity

[enseng]

Hi,

Just got a crystal plus DI unit to filter my tap water, the PH for the tap water is about 9. I think it is too high for the marine tank right?

Mixing the water with Tropic Marine Salt, will the PH reduce after mixing? I measure the tank PH, it is about 8.6, maybe due to topping of water which cause the PH to rise (previously was about 8.3). What should I do to reduce the PH? Should I reduce it before pouring the newly mixed water to the tank or after?

I am abit confused about the relationship between PH, KH and alkanity. Can I say that raising the PH will cause the rise in KH and alkanity? I bought the Kent Marine Pro-buffer to raise the dKH level, will it increase the PH level as well? Saw seachem brand the PH buffer and reef builder (for KH) so I am a bit confused on the actual usage.

Need all your input on the above mentioned......

[Gouldian]

Hi,

Just got a crystal plus DI unit to filter my tap water, the PH for the tap water is about 9. I think it is too high for the marine tank right?

Mixing the water with Tropic Marine Salt, will the PH reduce after mixing? I measure the tank PH, it is about 8.6, maybe due to topping of water which cause the PH to rise (previously was about 8.3). What should I do to reduce the PH? Should I reduce it before pouring the newly mixed water to the tank or after?

I am abit confused about the relationship between PH, KH and alkanity. Can I say that raising the PH will cause the rise in KH and alkanity? I bought the Kent Marine Pro-buffer to raise the dKH level, will it increase the PH level as well? Saw seachem brand the PH buffer and reef builder (for KH) so I am a bit confused on the actual usage.

Need all your input on the above mentioned......

Hi bro,

I'll attempt to answer your queries as much as I can:

pH (power of Hydrogen) is a measurement of the acidity or alkalinity of a solution. A pH of 7 is considered to be "neutral", neither acid or alkaline. Thus a reading above 7 = alkaline and below 7 = acidic.

In our tank situation pH will go on a downtrend due to the addition of acid. These acids come from various sources are :

1) excess carbon dioxide (CO2) from respiration caused by lack of sufficient gas exchange

2) nitric acid from biological filtration (nitrification)

3) organic acids from metabolic wastes.

Respiration and metabolic wastes are a part of the ocean, but the reason that sea water pH does not change is that the water contains a number of chemicals, such as bicarbonate, calcium, carbonate, borate and hydroxide, all of which act as natural "buffers" that prevents the drop in pH.

In captive environment, pH can be maintain buffers such as carbonate and bi-carbonate. carbonate can be measure KH or dKH. The amount of "buffers" in sea water determines the alkalinity.

When respiration and metabolic wastes increase, buffers within the tank will be used to react and maintain the pH. However, when the buffers have been consumed, pH will start dropping. Thus you will usually notice a drop kH before you notice a drop in pH. Also, if you kH is normal and the pH is slightly low, you can sometime remedy the situation with having better aeration.

Ca is another ion that is needed by the livestocks for health and growth. Ca have a close relationship with kH as calcium carbonate, so when adding too much calcium carbonate, you will also notice increase in kH. Calcium can be liberated into free form calcium for a short period before precipitating into calcium carbonate. The period of calcium remaining a free ion depends on many factor 1 of which is due to magnesium (mg), thus keeping mg at optimum level will ensure calcium free ion be available in your tank for longer. This is also why, calcium have to be supplemented frequently even though we have sand bed derive from aragonite/oolitic.

HTH

[yikai]

Respiration and metabolic wastes are a part of the ocean, but the reason that sea water pH does not change is that the water contains a number of chemicals, such as bicarbonate, calcium, carbonate, borate and hydroxide, all of which act as natural "buffers" that prevents the drop in pH.

In captive environment, pH can be maintain buffers such as carbonate and bi-carbonate. carbonate can be measure KH or dKH. The amount of "buffers" in sea water determines the alkalinity.

When respiration and metabolic wastes increase, buffers within the tank will be used to react and maintain the pH. However, when the buffers have been consumed, pH will start dropping. Thus you will usually notice a drop kH before you notice a drop in pH. Also, if you kH is normal and the pH is slightly low, you can sometime remedy the situation with having better aeration.

HTH

wow bro excellent explanation

you explained the buffer system well...i believe even helping me with school work.. on the brownsten lowry conjugate acid base buffer thingy. previously didnt really understand how the buffer works, but after reading this i sort of understand.

[Gouldian]

wow bro excellent explanation

you explained the buffer system well...i believe even helping me with school work.. on the brownsten lowry conjugate acid base buffer thingy. previously didnt really understand how the buffer works, but after reading this i sort of understand.

Bro, this is just my layman understanding nia... :paiseh:

[yikai]

Bro, this is just my layman understanding nia... :paiseh:

haha well, its good enough to help me! at least now i understand the buffer...which is what im studying for now

[Gouldian]

haha well, its good enough to help me! at least now i understand the buffer...which is what im studying for now

Since you are studying buffer, you may want to share your insights.

[comycus]

Hi,

Just got a crystal plus DI unit to filter my tap water, the PH for the tap water is about 9. I think it is too high for the marine tank right?

Mixing the water with Tropic Marine Salt, will the PH reduce after mixing? I measure the tank PH, it is about 8.6, maybe due to topping of water which cause the PH to rise (previously was about 8.3). What should I do to reduce the PH? Should I reduce it before pouring the newly mixed water to the tank or after?

I am abit confused about the relationship between PH, KH and alkanity. Can I say that raising the PH will cause the rise in KH and alkanity? I bought the Kent Marine Pro-buffer to raise the dKH level, will it increase the PH level as well? Saw seachem brand the PH buffer and reef builder (for KH) so I am a bit confused on the actual usage.

Need all your input on the above mentioned......

My tap water pH is also about 9 before mixing, after mixing will drop to ~8.2. The other thing is maybe wanna check your ph monitor, might not be calibrated correctly.

Dunno why I can't seem to increase the pH of my tank above 8. It seems to stabilize at 8 no matter how much seachem reef buffer I use. There was once I added so much tt my KH shot up to 19 over 5 days!!! Prob one of the reasons Gouldian stated. As long as it doesn't drop below 8, I guess it should be fine right?

[richhang]

Since you are studying buffer, you may want to share your insights.

Hi bro,well explained.So if PH reads 8.4 can i assumed that KH and alkalinity are in optimun level.Bcos if the latter drops then PH will follow wise.

[sherman]

My tap water pH is also about 9 before mixing, after mixing will drop to ~8.2. The other thing is maybe wanna check your ph monitor, might not be calibrated correctly.

Dunno why I can't seem to increase the pH of my tank above 8. It seems to stabilize at 8 no matter how much seachem reef buffer I use. There was once I added so much tt my KH shot up to 19 over 5 days!!! Prob one of the reasons Gouldian stated. As long as it doesn't drop below 8, I guess it should be fine right?

I use to have this issue before.

I pour in buffer daily and the PH is still around 7.9 to 8.1

Recently I try to dose kalkwasser and the PH start to go up.

At the same time the calcium maintain at 460.

Seems that kalkwasser can push up PH better than buffer

[comycus]

I use to have this issue before.

I pour in buffer daily and the PH is still around 7.9 to 8.1

Recently I try to dose kalkwasser and the PH start to go up.

At the same time the calcium maintain at 460.

Seems that kalkwasser can push up PH better than buffer

ok thanks. will try to dose kalkwasser on drip at night... time to diy a drip system

[HellBliss]

i think cause kalk has a natural ph of 12? therefore it will raise ur ph.. but must be careful with it as accidental overdose is quite dangerous.. some people use kalk with CR together as the ph lowering effect of CR will be negated by the high ph of kalk..

[Gouldian]

I use to have this issue before.

I pour in buffer daily and the PH is still around 7.9 to 8.1

Recently I try to dose kalkwasser and the PH start to go up.

At the same time the calcium maintain at 460.

Seems that kalkwasser can push up PH better than buffer

Yes, Kalkwasser which is calcium hydroxide.

From my limited knowledge hydroxide have higher pH than carbornate thus adding too much kalk will increase the pH while Ca and kH may not increase much.

That's why tanks with high calcium demands (stonies dominated) will need to install a CR or dose 2 parts solutions rather than just dose kalkwasser to maintain the parameters.

HTH

[enseng]

wow..impressive explanation about PH, KH and alkanity....thank bro!

But my PH now is slightly higher at 8.6, what should I do to reduce it? Or i just leave it as it is since after the buffer has been consumed which result in drop in dK, the PH will drop? Am I right to say it?

[Gouldian]

wow..impressive explanation about PH, KH and alkanity....thank bro!

But my PH now is slightly higher at 8.6, what should I do to reduce it? Or i just leave it as it is since after the buffer has been consumed which result in drop in dK, the PH will drop? Am I right to say it?

pH 8.6 should be alright. Do note that pH will fluctuated during lights on and off and also at different parts of a large system.

pH will usually be the lowest before lights on as after lights off, respiration will slow push the pH low. So it is not uncommon to have pH fluctuating from 7.9 to 8.9 in the course of a day. If you have a pH monitor, you can constantly monitor the pH swing between lights on and off and from this you will be able to know the healthy pH fluctuation in your tank.

So what you need to do is to do a kH test, if kh is good then there should not be a cause of concerns.

HTH

[clee123]

pH 8.6 should be alright. Do note that pH will fluctuated during lights on and off and also at different parts of a large system.

pH will usually be the lowest before lights on as after lights off, respiration will slow push the pH low. So it is not uncommon to have pH fluctuating from 7.9 to 8.9 in the course of a day. If you have a pH monitor, you can constantly monitor the pH swing between lights on and off and from this you will be able to know the healthy pH fluctuation in your tank.

So what you need to do is to do a kH test, if kh is good then there should not be a cause of concerns.

HTH

Bro Gouldian is right... what I would do is to make sure that my kh is in the good range frist (9-11dh), then use that as the reference point to apply the appropreiate cause of action based on the situiation/condition.

For example, if my KH is in the good range and my PH is low..I would add buffer to bring PH into the good range or if my KH is in the good range but my PH is hight I would use PH minus or just do nothing at let the buffers being consumed...

However, sometime things are not just that simple.... in general calcuum and alkalinity are the two most common problems encountered in typical reef tank..

[sherman]

Magnesium is very important too.

It can affect both the calcium and alkalinity