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how to raise alkalinity

Freshwater Sucker Fish

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read the following on google true or false good or bad?

Dissolve 1 teaspoon of baking soda in a glass of water for each 10 gallons in the tank. Add it to the aquarium and wait 24 hours. If the rise in alkalinity is too extreme, it can kill the fish in the tank
 

essjay

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Baking soda shouldn't be used with fish in the tank. It is sodium hydrogen carbonate and fish have not evolved to cope with a lot of sodium in the water.

As CryptFan asked, why do you want to raise the KH?
GH pH and KH are all tied together. You can't alter one without altering all three, and this is not something to undertake unless absolutely necessary.
 

Byron

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read the following on google true or false good or bad?

Dissolve 1 teaspoon of baking soda in a glass of water for each 10 gallons in the tank. Add it to the aquarium and wait 24 hours. If the rise in alkalinity is too extreme, it can kill the fish in the tank
Aside from essjay's observation...this is also not an effective method anyway. The sodium carbonate (baking soda) is not a permanent buffer; as the aquarium matures, the organic accumulation will eventually overpower the buffering capability of the sodium carbonate. In other words, it doesn't work.

The only safe way to increase alkalinity is in connection with GH, and involves calcareous minerals/substances such as limestone, cortal, shell, etc, but calcium and magnesium need to be included (coral is calcium). Aragonite and dolomite work well. Years ago I used these for a buffering of the pH in a tank with fish requiring it. However, you are always making your life and that of the aquarium inhabitants much easier and safer by not messing with chemistry and selecting fish suited to your water.
 

Byron

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Because my water doest have enough for guppy fish its recommended to have 100-150 Mg/l I get 40ppm
There is more to this. First, there are three inter-connected aspects, GH (the general hardness which is basically dissolved calcium and magnesium in the water), the KH (carbonate hardness or Alkalinity), and pH. Generally, the higher the GH, the higher the KH and pH. Not always, but these do generally go together.

Fish are most affected by the GH, then pH. So with fish requiring moderately hard or harder water, such as guppies, the main consideration is the GH of the source water. The KH really doesn't matter, as the pH will tend to be basic (above 7) which such fish also need if the GH is on the hard side. And with a moderately hard GH, the KH will be comparable.

The same works in reverse. Soft water fish tend to also prefer acidic pH, and in soft or very soft water the pH will tend to be lower, though other things can impact this too.

So raising the KH without first raising the GH is not going to work. And once the GH is high (depending what it now is), the KH will correspond.
 

Colin_T

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read the following on google true or false good or bad?

Dissolve 1 teaspoon of baking soda in a glass of water for each 10 gallons in the tank. Add it to the aquarium and wait 24 hours. If the rise in alkalinity is too extreme, it can kill the fish in the tank
That is true.

Baking soda normally contains sodium bicarbonate, which will raise the pH of water very quickly.

If fish are exposed to sudden fluctuations in pH (either up or down), it can kill them.
If the pH drops suddenly and goes below 7.0, the fish can get acidosis.
If the pH goes up above 7.0 suddenly, the fish can get alkalosis.

In addition to this, high levels of sodium can damage some fish's kidneys. This is more common in soft water fishes like tetras, barbs, rasboras, gouramis, Bettas and angelfish. It is less of an issue for fish like livebearers (guppies, mollies, swordtails, platies), goldfish and rainbowfish.

A small amount of sodium bicarbonate used every now and then is not going to harm fish, but a safer alternative is calcium carbonate or calcium bicarbonate. You can buy these in powder form or just add some shells, limestone, dead coral rubble or dead coral skeleton to the tank. These will help neutralise acids in the water and stop the pH dropping too quickly.
NB, calcium carbonate is hard to dissolve in water and calcium bicarbonate is a better choice.

If you have soft water (GH under 150ppm), you can increase the GH, KH and pH by adding Rift Lake conditioner. This is designed to increase the GH, KH and pH for African Rift Lake cichlids but can also be used at a lower dose rate for livebearers.


Guppies, platies and swordtails do best when the GH is around 200ppm.
Mollies do best when the GH is above 250ppm.
 

essjay

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I do regular partial water changes to raise alkalinity slowly
This will only raise the KH to the level of the tap water. The OP wanted to raise it higher than that.

But yes, where KH is low water changes are a good way of maintaining the level of KH.
 

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