pH, Hardness and Chemicals/Binding

[Miles]

I see alot of chemicals that claim to remove the 'Hardness' from the water. How is that possible?

We have very hard water here, and I am curious of what the effects of such chemicals, or pH adjusters have on hard water? What about driftwood and almond leaves? Does it just mask the pH and add acidity to the water, or does it actually remove/bind the hardness? I have always been very curious about this..

Is RO filtration and other filters the only REAL way to remove actual hardness?

 

[Ornatapinnis]

In my opinion, to achieve a specific ph and hardness, the correct way is to start with R.O. / D.I. water and buffer to the desired parameter. I don't agree with just taking tap water and trying to adjust or change it. Many times this is a loosing battle that kills fish. Example; If your water is hard & alkaline but you want neutral or soft acidic water, adding the acid buffers often times don't work because the calcium carbonite is still in the water and over powers the acid buffer in a very short amount of time. The use of peat or similar is often usless or at best unstable. Yes, drift wood and peat will lower your ph & hardness overtime but most of us do water changes so often, we are adding buffers right back to our aquarium. The exception might be if a person had neutral water and buffered or if a person had 7.8 and wanted 8.5 and buffered it. My experiance is that if you don't remove the element(s) that are causing the undesirable parameter of your water, in most cases chemicals are at best a very temporary and a very unstable way to change the parameter. I have done some trial and error with mixing my tap water with R.O. water to achieve water with a low 7 PH. Also, don't used straight R.O., it has nothing in it, will cause multiple problems with water stability and fish health.

Joel

 

[HarleyK]

Hi Miles,

First of all, hardness is the concentration of alkaline earth metals, mostly calcium and magnesium, in water. Some water treatment plants remove them by adding a base and precipitate these metals as carbonates. Gererally, they're in water as hydrogen carbonates.

[Ca2+ + 2 HCO3-] + Ca(OH)2 ---> 2 CaCO3 + 2 H2O

As carbonates, they are much less soluble and, thus, out of the water.

Another way is to add polyphosphates. They form soluble complexes with those ions, "kind of" make them disappear. Which is mostly used in old detergents or modern dishwasher agents. This way, the carbonates (still dissolved in low concentrations) don't precipitate when the water is heated, and the heater cores remain clean.

I don't think either way is a real option in our hobby.

An ion exchanger (resin) simply exchanges alkaline earth metals (magnesioum, calcium) with alkali metals (sodium, postassium). That reduces the hardness, but high conductivity remains. The ion load doubles concentration-wise and stays constant charge-wise. No real help, either.

Is RO filtration and other filters the only REAL way to remove actual hardness?

Yes, reverse osmosis is. Downside: Lots of waste water. Pre-treatment with a resin (see above) could reduce that. Or you simply have a lot of water for your flowers...

HarleyK


on edit:

I forgot your driftwood question: peat, drift wood etc works by humic substances which a) adsorb ions and b) are slightly acidic. Their capacity is very limited, though. They only play a role if your water is already quite soft and you need it just a bit softer and slightly buffered in the acidic range.

pH adjustment does not change the calcium/magnesium concentrations. Thus, it does not alter the hardness. If you have carbonates in your tank, though (limestone, corals), acid will harden it up further by dissolving those carbonates

 

[repair]

Since I keep hearing about driftwood and how it discolors the water and it can change the hardness let me ask this question to clear things up for me.... ( I'm not that bright )

I have never had driftwood in any of my tanks but I'm getting ready to use some in a 90 gal tank that I'm going to set up in an office and after listening to everyone I'm not sure that I should use it.

This tank will have cichlids in it and the water will be 7.8 to 8.2 and it will be hard.

I will only see this tank once a month to do a water change of 40 to 50%. Does anyone see a problem, with this?

I have a lot of tanks at home and I should know these answers but humor me and make me feel better.

I have heard people say not to do water changes of 50% but I have never had a problem with doing this but am I missing something?

Thanks for the help.

 

[HarleyK]

Hi repair,

I've never had a tank without driftwood. In my eyes, it's just a great way to decorate a tank. Driftwood will not change your water's hardness. Especially if you have hard water to begin with. It might take up some hardness in the first few weeks in a very soft-water tank. But that's noticible in a tank with around 1-2 degree hardness only. Secondly, it will color your water brown. That's nature. Not much you can do about it except to change water or to filter thru carbon. I personally find that the clear (!!) brownish tint is a nice thing. Kinda like peat adds some color, too. Whereas driftwood has by far not the effects on water chemistry as peat has.

HarleyK

 

[drdpc]

Hi
I'm learning a lot of things here in the forum, but almost every brazilian aquarists use very simple solutions!
The weekly change of part of the water is a solution to control ph, density, hardnees!, waste! Here, the chemical conditioners are expensive, so we use leaves of some trees, shells, rain water or the ice that appears on the wall of freezers!
I believe that where you live you will find various ways to put your tanks the way you want!