Does "hard" Mean "alkaline"?

[fishstick]

I read in PFK that cichlid shell-dwellers need hard water (not critical) also alkaline (critical), can anyone explain the difference?

 

[nmonks]

Hardness refers to the concentration of salts dissolved in the water. Alkalinity refers to the pH.

The two things are usually connected, i.e., hard water is often alkaline. But it is possible to raise the pH of pure water to alkaline levels without making water hard, by adding alkaline substances such as ammonia. In aquaria, this is rarely what happens, and almost always you will make hard, alkaline conditions together by using a calcareous substrate (such as coral sand) to "buffer" the water.

Buffering basically means dissolving; what happens is the coral sand slowly dissolves, making the water hard and alkaline. Once it reaches certain point, which happens to be an ideal pH and hardness, it stops dissolving. Actually, to be precise, it reaches a point where it reaches an equilibrium with the water, dissolving and precipatiting out at the same rate.

Hard water is best if you are keeping fish that like alkaline conditions because of this buffering effect. If, for some reason, the pH drops (e.g., you do a water change) the coral sand will "buffer" the new water, restoring the desired pH. Hence, while you can have an alkaline aquarium without high hardness, it is invariably best to have an aquarium with both hard AND alkaline water conditions.

Cheers,

Neale

 

[fishstick]

Hardness refers to the concentration of salts dissolved in the water. Alkalinity refers to the pH.

The two things are usually connected, i.e., hard water is often alkaline. But it is possible to raise the pH of pure water to alkaline levels without making water hard, by adding alkaline substances such as ammonia. In aquaria, this is rarely what happens, and almost always you will make hard, alkaline conditions together by using a calcareous substrate (such as coral sand) to "buffer" the water.

Buffering basically means dissolving; what happens is the coral sand slowly dissolves, making the water hard and alkaline. Once it reaches certain point, which happens to be an ideal pH and hardness, it stops dissolving. Actually, to be precise, it reaches a point where it reaches an equilibrium with the water, dissolving and precipatiting out at the same rate.

Hard water is best if you are keeping fish that like alkaline conditions because of this buffering effect. If, for some reason, the pH drops (e.g., you do a water change) the coral sand will "buffer" the new water, restoring the desired pH. Hence, while you can have an alkaline aquarium without high hardness, it is invariably best to have an aquarium with both hard AND alkaline water conditions.

Cheers,

Neale

Hardness refers to the concentration of salts dissolved in the water. Alkalinity refers to the pH.

The two things are usually connected, i.e., hard water is often alkaline. But it is possible to raise the pH of pure water to alkaline levels without making water hard, by adding alkaline substances such as ammonia. In aquaria, this is rarely what happens, and almost always you will make hard, alkaline conditions together by using a calcareous substrate (such as coral sand) to "buffer" the water.

Buffering basically means dissolving; what happens is the coral sand slowly dissolves, making the water hard and alkaline. Once it reaches certain point, which happens to be an ideal pH and hardness, it stops dissolving. Actually, to be precise, it reaches a point where it reaches an equilibrium with the water, dissolving and precipatiting out at the same rate.

Hard water is best if you are keeping fish that like alkaline conditions because of this buffering effect. If, for some reason, the pH drops (e.g., you do a water change) the coral sand will "buffer" the new water, restoring the desired pH. Hence, while you can have an alkaline aquarium without high hardness, it is invariably best to have an aquarium with both hard AND alkaline water conditions.

Cheers,

Neale

Hardness refers to the concentration of salts dissolved in the water. Alkalinity refers to the pH.

The two things are usually connected, i.e., hard water is often alkaline. But it is possible to raise the pH of pure water to alkaline levels without making water hard, by adding alkaline substances such as ammonia. In aquaria, this is rarely what happens, and almost always you will make hard, alkaline conditions together by using a calcareous substrate (such as coral sand) to "buffer" the water.

Buffering basically means dissolving; what happens is the coral sand slowly dissolves, making the water hard and alkaline. Once it reaches certain point, which happens to be an ideal pH and hardness, it stops dissolving. Actually, to be precise, it reaches a point where it reaches an equilibrium with the water, dissolving and precipatiting out at the same rate.

Hard water is best if you are keeping fish that like alkaline conditions because of this buffering effect. If, for some reason, the pH drops (e.g., you do a water change) the coral sand will "buffer" the new water, restoring the desired pH. Hence, while you can have an alkaline aquarium without high hardness, it is invariably best to have an aquarium with both hard AND alkaline water conditions.

Cheers,

Neale

Hardness refers to the concentration of salts dissolved in the water. Alkalinity refers to the pH.

The two things are usually connected, i.e., hard water is often alkaline. But it is possible to raise the pH of pure water to alkaline levels without making water hard, by adding alkaline substances such as ammonia. In aquaria, this is rarely what happens, and almost always you will make hard, alkaline conditions together by using a calcareous substrate (such as coral sand) to "buffer" the water.

Buffering basically means dissolving; what happens is the coral sand slowly dissolves, making the water hard and alkaline. Once it reaches certain point, which happens to be an ideal pH and hardness, it stops dissolving. Actually, to be precise, it reaches a point where it reaches an equilibrium with the water, dissolving and precipatiting out at the same rate.

Hard water is best if you are keeping fish that like alkaline conditions because of this buffering effect. If, for some reason, the pH drops (e.g., you do a water change) the coral sand will "buffer" the new water, restoring the desired pH. Hence, while you can have an alkaline aquarium without high hardness, it is invariably best to have an aquarium with both hard AND alkaline water conditions.

Cheers,

Neale

Hardness refers to the concentration of salts dissolved in the water. Alkalinity refers to the pH.

The two things are usually connected, i.e., hard water is often alkaline. But it is possible to raise the pH of pure water to alkaline levels without making water hard, by adding alkaline substances such as ammonia. In aquaria, this is rarely what happens, and almost always you will make hard, alkaline conditions together by using a calcareous substrate (such as coral sand) to "buffer" the water.

Buffering basically means dissolving; what happens is the coral sand slowly dissolves, making the water hard and alkaline. Once it reaches certain point, which happens to be an ideal pH and hardness, it stops dissolving. Actually, to be precise, it reaches a point where it reaches an equilibrium with the water, dissolving and precipatiting out at the same rate.

Hard water is best if you are keeping fish that like alkaline conditions because of this buffering effect. If, for some reason, the pH drops (e.g., you do a water change) the coral sand will "buffer" the new water, restoring the desired pH. Hence, while you can have an alkaline aquarium without high hardness, it is invariably best to have an aquarium with both hard AND alkaline water conditions.

Cheers,

Neale

Hardness refers to the concentration of salts dissolved in the water. Alkalinity refers to the pH.

The two things are usually connected, i.e., hard water is often alkaline. But it is possible to raise the pH of pure water to alkaline levels without making water hard, by adding alkaline substances such as ammonia. In aquaria, this is rarely what happens, and almost always you will make hard, alkaline conditions together by using a calcareous substrate (such as coral sand) to "buffer" the water.

Buffering basically means dissolving; what happens is the coral sand slowly dissolves, making the water hard and alkaline. Once it reaches certain point, which happens to be an ideal pH and hardness, it stops dissolving. Actually, to be precise, it reaches a point where it reaches an equilibrium with the water, dissolving and precipatiting out at the same rate.

Hard water is best if you are keeping fish that like alkaline conditions because of this buffering effect. If, for some reason, the pH drops (e.g., you do a water change) the coral sand will "buffer" the new water, restoring the desired pH. Hence, while you can have an alkaline aquarium without high hardness, it is invariably best to have an aquarium with both hard AND alkaline water conditions.

Cheers,

Neale

Thankyou very much Neale, I shall buy some coral sand to make sure. Fishstick.