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Water Chemistry

2692 Views 4 Replies 4 Participants Last post by  Keywan
Hi everyone

I'm in the process of setting up a low tech, planted Australian native Rainbowfish aquarium, but have run into some issues concerning the rather weird water found in my area.

My water parameters are as follows:

pH: 7.7
General Hardness(GH): 44 ppm
Alkalinity(KH): 36 ppm

A link to the source of my information: Water Quality | ACTEW

Bellow are the ideal water parameters for Rainbowfish:

pH: 6.5-7.8
General Hardness(GH): 50-250 ppm
Alkalinity(KH): 50-200 ppm

So I need to increase the GH and KH to stabilize the pH, but at the same time I don't want to raise the pH, which is just within the margin it needs to be.

Does anyone have any suggestions as to what I should add to the water the raise the GH and KH without also increasing the pH?

In all honesty I'm not even sure what would be causing such soft water to have such a high pH in the first place, but tests at home confirm that information from the website is correct.

This is my first aquarium and my understanding of water chemistry is very patchy, so any prevailing wisdom would be most appreciated. :-D
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From what I have seen, water chemistry for rainbowfish is all over the charts. Apparently, the origins of the fish vary widely and the PH, etc. accordingly. I'd research the many rainbowfish varieties and go with those that fit you water the best. My water is softer than yours and my PH is over 8. PH is often altered by water utilities to offer protection for pipes and appliances. Trying to change your water to match fish is very difficult to pull off consistently.
I agree. Parameters vary from species to species--we only have three (the more common) species of rainbowfish in our profiles, and their parameters vary from soft to moderately hard, depending upon which species. Confirming the preferred params for the species you are intending is your first step.

Then there is the issue of "preferred," which is a guide that one should not stray too far from, in general terms, but it is not cut in stone either.

There are safe methods to raise GH without affecting pH. I have to do this with my near-zero GH in the tap water, and I do it for the plants since I keep soft water fish.

Our profile rainbows are here:
Atherinid Species

Byron.
I think we sometimes over think water chemistry....I think ;-)
(I think, therefore I am....I think)

Without a doubt, the water in much of the tropics and especially the Amazon is very pure and very soft. However, many of the fish we have from the LFS were pond raised in the south or tank raised anywhere. Born and raised in a wide range of water parameters from very soft to very hard, somewhat acidic to very alkaline.

I think the most important thing we can do is not so much to try and match and maintain a chemistry totally different than our local water that we 'think' our fish would prefer, but to properly acclimate the fish we bring home and maintain the tank as stable as possible.
I think we sometimes over think water chemistry....I think ;-)
(I think, therefore I am....I think)

Without a doubt, the water in much of the tropics and especially the Amazon is very pure and very soft. However, many of the fish we have from the LFS were pond raised in the south or tank raised anywhere. Born and raised in a wide range of water parameters from very soft to very hard, somewhat acidic to very alkaline.

I think the most important thing we can do is not so much to try and match and maintain a chemistry totally different than our local water that we 'think' our fish would prefer, but to properly acclimate the fish we bring home and maintain the tank as stable as possible.
I wholeheartedly agree, I do think a lot of people over think the chemistry of their water. A stable pH is far more important then one that perfectly matches the environment that the fishes ancestors lived in.

The species of Rainbowfish that I am most interested in is Melanotaenia splendida inornata. They are found all over the top end of Australia, and the water conditions they are found in change dramatically between the wet and dry seasons. My GH and KH are close to the minimum they need to be, so I think I will use magnesium sulphate and calcium chloride to bring them up to scratch.

Thanks everyone for your advice.
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