[MakoMaui]

Hey, everyone. I'm reading up on freshwater aquarium-keeping through a book that I've purchased, and I am on the topic of pH and chemicals inside the water. I had trouble following along, due to its usage of chemistry equations and terminology. I've never took chemistry and I do not understand it. I looked up pH on google and on the wikipedia page, it just seemed even more difficult and advanced. Can anyone simplify pH to me in the most basic way?

 

[JDM]

Neutral pH is 7. Over 7 is basic or alkaline and under 7 is acidic.

pH is "power of Hydrogen" but all the chemistry stuff really doesn't matter as long as you understand that two basic premises relating to keeping fish.

1) different species of fish have different tolerances based on their native environments. Usually the range that we track for fresh water fish is between 6 and 8. Ideally the water pH should be in the middle of their normal tolerance. ie. a fish with a tolerance of 7 to 8 would do best in a pH of 7.5 as it will swing a bit even just over the course of the day as CO2 levels go up and down... a whole other topic.

2) Fish don't do well with wide swings in pH so messing with the pH can affect the fish negatively. Just the fact that the water swings from one level of acidity alkalinity to another is bad. Chemically lowering the pH can result in it spiking back up as the water tends to try to maintain it's original pH based on it's original composition.

Another interesting point is that ammonia has two types in water. Ammonia and ammonium. The first is toxic and the second is not. They are in a state of equilibrium and the higher the pH the higher the ammonia to ammonium ratio. The lower the pH the lower the ammonia to ammonium ratio. This makes overall ammonia levels more dangerous to fish in a higher pH water. I believe that there are far more fish that have lower pH tolerances as I have very hard water with a pH in the high 7's (harder water tends to have higher levels) so my fish list was fairly short.

The best course is to select fish that match your source water parameters to make it easier when it comes time to change water... sometimes this means not keeping the fish that you might want initially. When keeping multiple species their pH tolerances, just like hardness and temperature tolerances, should be very similar so as to have all of them near the middle of their respective ranges.

Hope this helps a bit.

Jeff.

 

[Byron]

You might also get some help from my article on the topic, here:
http://www.tropicalfishkeeping.com/freshwater-articles/water-hardness-ph-freshwater-aquarium-73276/

In places it might seem fairly techical, but it is impossible to understand without some of this.

Byron.

 

[MakoMaui]

You guys just about summed it up for me. That seems pretty basic when put in that way. Hopefully all of the technical stuff becomes more clearer though in time. But if you pick fish based on the local water supply, how limited is the possible fish selection? Aren't there quite a few fish for every water parameter? Thanks for the help.

 

[JDM]

You guys just about summed it up for me. That seems pretty basic when put in that way. Hopefully all of the technical stuff becomes more clearer though in time. But if you pick fish based on the local water supply, how limited is the possible fish selection? Aren't there quite a few fish for every water parameter? Thanks for the help.

Yes, it's a matter of fish mix though. Picking fish based on similar parameters gets harder the more fish you try to squeeze in and there is the temperament to deal with, some long finned sedate fish can't be with active fish or fish that might be prone to fin nipping or aggressive behaviour.

I have a set of issues to deal with between really hard water, higher pH, warmer temperatures and particular fish issues that reduced my list to about 10 fish. I think Byron has somewhere over 20 species in one of his tanks but his water is really soft with a low pH which lends itself well to more fish.

Basically, go through the fish profiles and compile a list that fit your water parameters and tank size. If you have a favourite fish that you want first, jot down all the parameters for that fish (pH, hardness, temperature, tank size) then go through and list the fist that have very similar needs. Then eliminate ones that are not a good temperament match.

It may take a little time but it will pay off big when you don't have to mess with the water and you don't have issues between fish to deal with. There are enough things to worry about when things are going right with a new tank that you don't want avoidable issues cropping up to really complicate things.

Jeff.

 

[Byron]

You guys just about summed it up for me. That seems pretty basic when put in that way. Hopefully all of the technical stuff becomes more clearer though in time. But if you pick fish based on the local water supply, how limited is the possible fish selection? Aren't there quite a few fish for every water parameter? Thanks for the help.

All fish have their preferred range to which they have evolved over thousands of years, so they will function best within that range; by this I mean their internal workings or physiology functions best in the specific range and that makes the fish healthier. The further outside their preferred range they are, the harder their systems have to work just to "live," and this wears down the fish and weakens it. Obviously this range varies, from fish that absolutely must have moderately hard water to fish than need very soft water with many along the way between the two opposites.

As my article I previously linked points out, the GH (the measure of the mineral hardness) is unlikely to change much in the aquarium from what it is out of the tap. The pH can vary, depending upon the GH and other factors in the aquarium. So knowing the GH and KH and pH of your tap water helps to select fish suited to those parameters.

We're only guessing without knowing the numbers for your water, but generally speaking there are usually quite a number of fish that can manage.

Byron.