The Chemistry Side Of Things...

[altselgreen]

Hi guys,

Well, I was in biology class today and we were talking about acids and alkalis. We were doing an experiment to do with alkali metals and how they react with water. The teacher put universal indicator into the water and it turned green, as a neutral solution usually does. I then had a thought, why do we, as fishkeepers have acid and alkali waters? If water is neutral, how come in fishkeeping we all talk about acidic water and alkali waters? I then thought could it be to do with the chlorine? We take away the chlorine causing the water to become un-neutral?

Then I thought, hang on, I actually know nothing about the water in my fish tank. I dont actually know what nitrites and nitrates are. All my LFS told me when I started was that I need to check the water to see if its able for fish to live in it. So, I took it to the shop and they told me if it was alright or not, and how long I had left until I could put some fish in. They never told me anything about the chemistry side to fishkeeping. So thats why I'm asking. Could anyone explain to me the chemistry of the hobby? (If that makes sense?) Or does anyone have a good link I can ponder?

I will stop blabbing now, but I really want to find this out.

Thanks

 

[three-fingers]

I then had a thought, why do we, as fishkeepers have acid and alkali waters? If water is neutral, how come in fishkeeping we all talk about acidic water and alkali waters?

Because the water in your fish tank is either acid or alkali . The pH indicator and strips used in school aren't very accurate. An aquarium pH test kit is more sensative. Pure water is pH 7, and lot's of places tap water is around 7 too, but it depends where you live and where your water comes from.

Knowing you pH is useful for deciding what type of fish you would be good at keeping. Some fish like ones from the Amazon (angelfish, discus, tetras ect) like acidic water of anywhere between pH 6 and 7 (though in some cases down to pH5) and some fish like live bearers like alkaline water between pH7 and 8.

This is a pretty good link: [URL="http/www.thetropicaltank.co.uk/wchem.htm"]http/www.thetropicaltank.co.uk/wchem.htm[/URL] .

I wish they would teach chemistry in relation to aquariums in school...my grades may suddenly improve . Seriously though, chemistry's a pretty good subject.

 

[Bignose]

That is an awfully big request. There is a tremendous amount of chemistry involved in fishkeeping. Do you have a specific first question that you'd like answered? "[T]he chemistry of the hobby" is exceptionally vague.

 

[Chaz]

Being a bad chemist but slightly better at fish I would say because when you actually get the water from the tap the water is already acidic/alkaline . at a gcse level it is how readly h+ ions for in solution (Please dont kill me if i get it wrong.... ) ,,,,,

 

[Squidman]

Being a bad chemist but slightly better at fish I would say because when you actually get the water from the tap the water is already acidic/alkaline . at a gcse level it is how readly h+ ions for in solution (Please dont kill me if i get it wrong.... ) ,,,,,

Are you saying that the tap is never soft and slightly acidic when untreated?

 

[Chaz]

Well depending on where you live the water could be anything. Where I live the water pH is 7.2 but a friend near me has a pH of 6.7 so e uses water from his lfs

 

[andywg]

Well depending on where you live the water could be anything. Where I live the water pH is 7.2 but a friend near me has a pH of 6.7 so e uses water from his lfs

He uses seperate water because his is 6.7? May I ask why? Even if he wants rift valley cichlids he will just add some calcium based rocks and substrate.

 

[The-Wolf]

there is a beginners guide to basic water chemistry
http/www.fishforums.net/content/Tropical...In-Your-Water-/
however, take Bignoses' ( A recognised chemist) advise and ask a specific question as water chemistry is a very complicated subject with many chemical processes effecting other processes.

 

[eschaton]

From my understanding, the following play the main role in tank PH:

Carbon Dioxide - Often used to improve plant growth in tanks. Lowers your tank PH.
Bogwood - Releases tannins which lower your PH
Particulate Organic Material - Over time, if allowed to build up, will lower your PH

Dissolved minerals in tapwater - generally raise your PH. This is especially a concern in areas like the south of England, with alkaline/chalky soils - less so in areas where soils are clay based and neutral. In areas with any water hardness the PH of tanks will rise over time, as water evaporates and new water is used to "top off."

 

[CFC]

Pure water (rain for instance) is known as Basic water and has a pH of 7 due to its lack of TDS (total dissolved solids). Acids and Alkelines dissolve easily in basic water, decaying organic matter releases humic acids so where there are large amounts of leaves and other plant matter that fall into the water the water will usually be acidic. In areas where the water passes through or over lots of calcium based rocks the water will take up some of the calcium and become akeline, also city water plants add calcium to tapwater as acidic water attacks the pipelines.

 

[PRW1988]

Ph refers to the possibility of Hydrogen, or how acidic or alkalin the water is. In some areas of the world the soil releases a Ph into the water changing the Ph of the water, some fish (such as discus) thrive in this acidic water. Hard waters (alkalin) are caused by calicum being released. African cichlids and many other cichlid species have heavy calcium stones in the water that they inhabit, that's why they've adapted to these conditions to live.

Ammonia comes from fish waste, but not only this, it's released by all forms of waste and decomposition, it is a high toxic substance in large quantities which is why you want little or none(preferbly none) in your aquarium. Nitrites are the second toxic substance released from ammonia, when tiny little bacterium begin to break down the ammonia Nitrites are produced by their waste. Eventually another bacterium will come along and begin to break down the Nitrites into Nitrates, these are the least toxic substance in the aquarium, however in massive quantities they can be deadly. Water changes help to remove nitrates from the water, aswell, the benificial bacteria in your tank help to break down the nitrates aswell, although not aswell as changing the water and adding a pure, nutreal Ph water (7.0).


Hope this helps.