Ph

[Fay]

How do you test your ph?

I am not happy with the test kits seem to be a bit hit and miss

[rossco]

Yeah, I feel the same about test kits. I don't think I'm colour blind but its a bit of a guesstimate what colour it is sometimes but a big difference in pH!

[wasp]

Seachem put out an excellent one although I haven't seen them for a while.

[slappers]

if you want something good

There was a time when the measurement of pH, conductivity and relative humidity could be performed by complicated apparatus and trained laboratory technicians. The two methods of measuring these parameters were on opposite ends of the spectrum. At one end, you had the traditional pH litmus paper and kits with low resolution. The other method required training and complicated equipment to perform the analysis. The latter method had extremely high resolution, but could not be performed by everyone. Hanna introduced the pHep® in 1986. This pocket-sized meter literally replaced pH litmus paper for millions of users worldwide. The powerful electronics provided the operators with unparalleled accuracy, great repeatability, long battery life, and above all, an LCD where measurements could be read easily. Hanna knew that this was the answer to pH measurement problems! Since the advent of pHep®, Hanna has not only improved the pHep® family by adding waterproof models, but has expanded the line of Pocket Meters to cover areas such as conductivity, relative humidity and salinity. Hanna’s commitment to provide innovative, easy-to-use instruments continues with the introduction of testers featuring new ergonomic, and much more rugged casings, as well as larger LCDs for easier viewing from any angle. Add to these the precision of custom microprocessors and you have convenience and accuracy, in pocket size instrumentation.

[Fay]

How much are they Slappers

[slappers]

not to sure but can find out on tuesday for a price be around $180 to $250 but dont quote me on that

[Fay]

Big $'s Can you get them?

[reef]

http://www.trademe.co.nz/Browse/SearchResults.aspx?searchtype=GENERAL&searchstring=ph+meter&searchregion=100&go.x=26&go.y=10

[Fay]

Reef which one is the best?

[jetskisteve]

I have at least 2 Hanna's laying around that I dont use, I never check PH

[slappers]

there you go fay :bounce: :bounce:

[reef]

You pay for what you get, the ones listed will last a year or so, dont get second hand as you cant change the probes.

Its a good idea to check ph monthly.

[Duke]

Fay I'm looking at this also... let me know what you buy.

[Fay]

Question for Layton:

If I keep my KH stable does that mean my PH is O.K. as well or do I have to test for PH

[Fay]

Reason for asking about this:

At the moment I am keeping a strict eye on my KH because of my Nitrates while I try and address the problem.

I understand there is a difference between baking soda and baked baking soda, the second raises the Ph and I should watch the ph when adding.

Hence my interest in PH at the moment

I am running my Kh 12.5

Layton am I on the right track?

[Pies]

American Marine do a PinPoint meter, its generally regardard as one best PH units, they are fairly cheap, under NZ $100 and have probes that can be replaced. Its the probe the dictates accuracy, and the American Marine probes are standard (BNC connector) and can be used on IKS/OCT/NEPTUNE computers or other PH controllers/meters.

I have 1, its hooked up and running 24/7. I am on my second probe in 4 years, but I will replace it this year. I found after about 1.5years the probes is unaccurate between .3 & .5, which is enough of a swing to make me replace it. Probes are about $35usd.

KH is your ability to buffer your PH, it isn't always an indicator of desirable PH levels, and you should check your PH regulary and you should check it at different intervals during the day, as PH and PH stability are effected with the light cycle of the tank. I check my PH several times a week, and when its out of normal paramaters I check my CA reactor, 9 times out of 10 my bubble count is up/down which is effecting the tanks PH.

Pie

[lduncan]

Generally yes. If you KH is in normal ranges, your pH will be fine.

The one thing which affects the relationship between KH and pH is CO2.

For example, if you have a buildup of CO2 around your tank, then although your KH may be fine, you may find that pH is lower than normal.

Or if you run a calcium reactor, you may find that pH is lower than it otherwise would be because of excess CO2.

I haven't tested pH in years. KH is far more important.

Baking soda temporarily lowers pH (while the carbonate / bicarbonate equilibrium establishes itself)

Baked Baking soda when added to salt water results in a pH of around 8.3, so it shouldn't raise pH (unless pH is low already)

Honestly it's not really worth watching pH when adding baking soda, or baked baking soda, in small amounts.

If you're adding a LOT of baking soda then, maybe yes, but it's only a temporary effect.

Layton

[reef]

am running my Kh 12.5

Too high , natural sea water is about 8kh. Keeping KH at 12.5 makes it hard to keep calcium up.

My Kh runs between 7-8kh and is a problem to keep it their, so it must be very hard to keep KH at 12.5

[Fay]

First of all I would like to welcome Pies back thank you for helping me with this, I knew Ph is something you watch and appreciate your input.

[Fay]

Also thanks Layton I can't get my head around it properly, if we are adding fresh water for top up everyday why isn't it lowering our Ph.

Reef I found something on keeping the Kh higher than natural seawater if your nitrates are high, I will go and see if I can find it.

[lduncan]

Also thanks Layton I can't get my head around it properly, if we are adding fresh water for top up everyday why isn't it lowering our Ph.

Reef I found something on keeping the Kh higher than natural seawater if your nitrates are high, I will go and see if I can find it.

That's a hard question to answer simply. You have to understand what pH actually is, as well as how buffer solutions and chemical equilibrium work. I could give it a go, but it would take a while, and probably wouldn't be particularly interesting, there's a bit of chemistry and maths involved.

As for the KH being high. I disagree. I think it's a good thing to keep KH higher when nitrates and phosphates are higher. Something i've touched on before with C:N: P ratio's (Redfield).

Also carbon in the form of alkalinity is limiting in the calcification process, not calcium. You can safely trade off calcium levels for increase alkalinity. Calcium of 350 seems to be a critical value in the trade off. Anything above 350 is fine.

Layton

[reef]

Keeping high Kh might help slightly but i doubt it will lower your Nitrates,

Best to find the cause of the high nitrates, For most it is the load of the tank as the more fish you have then more food you have to add.

25ppm is not that high to worry about if you have mainly LPS and soft coral. high nitrates will actually make them grow quicker.

Try nitrates reactor with sulphur balls, They work and are totally underrated. i quess not enough marketing.

I would up your dose of prodibio/bio digest to once a week for a month. also need to add biotum to feed the bactaria in the bio digest.

[Fay]

Reef I am not keeping my KH up to lower my nitrates.

[Fay]

Some of what I read but not the bit I am looking for.

Alkalinity

Like calcium, many corals also use "alkalinity" to form their skeletons, which are composed primarily of calcium carbonate. It is generally believed that corals take up bicarbonate, convert it into carbonate, and then use that carbonate to form calcium carbonate skeletons. That conversion process is shown as:

HCO3- à CO3-- + H+

Bicarbonate à Carbonate + acid

To ensure that corals have an adequate supply of bicarbonate for calcification, aquarists could very well just measure bicarbonate directly. Designing a test kit for bicarbonate, however, is somewhat more complicated than for alkalinity. Consequently, the use of alkalinity as a surrogate measure for bicarbonate is deeply entrenched in the reef aquarium hobby.

So, what is alkalinity? Alkalinity in a marine aquarium is simply a measure of the amount of acid (H+) required to reduce the pH to about 4.5, where all bicarbonate is converted into carbonic acid as follows:

HCO3- + H+ à H2CO3

In normal seawater or marine aquarium water, the bicarbonate greatly dominates all other ions that contribute to alkalinity, so knowing the amount of H+ needed to reduce the pH to 4.5 is akin to knowing how much bicarbonate is present. Aquarists have therefore found it convenient to use alkalinity as a surrogate measure for bicarbonate.

One important caveat to this surrogate measure is that some artificial seawater mixes, such as Seachem salt, contain elevated concentrations of borate. While borate is natural at low levels, and does contribute to pH stability, too much interferes with the normal relationship between bicarbonate and alkalinity, and aquaria using those mixes must take this difference into account when determining the appropriate alkalinity level.

Unlike the calcium concentration, it is widely believed that certain organisms calcify more quickly at alkalinity levels higher than those in normal seawater. This result has also been demonstrated in the scientific literature, which has shown that adding bicarbonate to seawater increases the rate of calcification in Porites porites.4 In this case, doubling the bicarbonate concentration resulted in a doubling of the calcification rate. Uptake of bicarbonate can apparently become rate limiting in many corals.5 This may be partly due to the fact that both photosynthesis and calcification are competing for bicarbonate, and that the external bicarbonate concentration is not large to begin with (relative to, for example, the calcium concentration).

For these reasons, alkalinity maintenance is a critical aspect of coral reef aquarium husbandry. In the absence of supplementation, alkalinity will rapidly drop as corals use up much of what is present in seawater. Most reef aquarists try to maintain alkalinity at levels at or slightly above those of normal seawater, although exactly what levels different aquarists target depend a bit on the goals of their aquaria. Those wanting the most rapid skeletal growth, for example, often push alkalinity to higher levels. I suggest that aquarists maintain alkalinity between about 2.5 and 4 meq/L (7-11 dKH, 125-200 ppm CaCO3 equivalents), although higher levels are acceptable as long as they do not depress the calcium level.

Alkalinity levels above those in natural seawater increase the abiotic (nonbiological) precipitation of calcium carbonate on objects such as heaters and pump impellers. This precipitation not only wastes calcium and alkalinity that aquarists are carefully adding, but it also increases equipment maintenance requirements. When elevated alkalinity is driving this precipitation, it can also depress the calcium level. A raised alkalinity level can therefore create undesirable consequences.

I suggest that aquarists use a balanced calcium and alkalinity additive system of some sort for routine maintenance. The most popular of these balanced methods include limewater (kalkwasser), calcium carbonate/carbon dioxide reactors, and the two-part additive systems.

For rapid alkalinity corrections, aquarists can simply use baking soda or washing soda to good effect.

[slappers]

im lost