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Apr 9, 2020
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Hi, I have a freshwater 55 gallon tank that im re-doing and am uncertain what to stock it with.

Here are some of the ideas I'm playing around with so far:
- Discus with some sort of tetras
- Angels with some sort of tetras
Maybe add loaches too.

Are these good combinations? What would be your recommendations or changes? What stocking ideas do you think would be better?
We need to know your GH before we can give suggestions :)
You should be able to find this info on your water providers website
It also depends on the temperature that you're going to maintain. If you're wanting to keep discus, then you need to find a tetra species that can handle high temperatures.
The Water here is pretty hard I think its Ph is 9 I think. I don't know what GH is though.
The Water here is pretty hard I think its Ph is 9 I think. I don't know what GH is though.
If you're going to keep soft water fish, then you need RO water. You can buy a gallon of RO water at your LFS or purchase your own RO unit.
What are the tank dimensions (length x width x height)?

What is the GH (general hardness), KH (carbonate hardness) and pH of your water supply?
This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).

pH is the measurement used to tell us if something is an acid, neutral or alkaline/ base. Pure distilled water has a no mineral content and a pH of 7.0 and is considered neutral.
If something breaks down in pure water the pH drops and becomes acidic (pH goes below 7.0).
If minerals are added to pure water the pH goes up and becomes basic or alkaline (pH goes above 7.0).

Carbonate Hardness (KH) is the measurement of carbonates and bicarbonates in the water. These normally increase the pH. When there are acids in the water, the acids cause the pH to drop. If there are plenty of carbonates/ bicarbonates in the water, they neutralise the acids and help stop the pH from dropping.

General Hardness (GH) is the measurement of minerals in the water and usually measures calcium and magnesium chlorides. The more calcium and or magnesium chlorides in the water, the harder it is.

If you have hard water, it contains lots of minerals and it usually contains lots of carbonates and bicarbonates. To lower the hardness, you dilute the hard water with soft water. Reverse osmosis (r/o) water, distilled water and rain water have no minerals and is very soft water. Mixing some of this soft water with the hard water will reduce the GH, KH and pH of the hard water.

If you want to reduce the pH, you can add small amounts of acidic substances like carbon dioxide (CO2), peat moss, drift wood and things like sodium biphosphate to lower the pH. These acids get neutralised by the carbonates/ bicarbonates and when the carbonates and bicarbonates have been used up, the pH drops.

To increase the GH you add minerals like calcium and magnesium chloride.

To increase the KH you add carbonates and bicarbonates (baking soda is sodium bicarbonate).
When you add carbonates & bicarbonates the pH will go up.

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