Alkalinity, do I really need it?

Question

So I've been using distilled water in my fish tank, intially my alkalinity was at 80. Within a couple days it dropped to 0 and has stayed there. From what I understand alkalinity helps the water resist pH changes? But then I read alkalinity is bad for the fish's gills and eyes?

So whats the deal, is having my alkalinity at 0 bad? Is there anything I can do to modify the alkalinity if I should have some? What is a normal / ideal alkalinity level?

Thanks in advance!

Answer 1

It is my opinion that yes, every tank needs a little alkalinity. You need it to help resist pH changes from occuring or doing so at a fast rate that could harm your fish. With a 0 alalinity even a few hours of power outage could cause your pH to drop very quickly and into a danger zone for your fish. If your fitler quit, same thing The alkalinity provides a buffer against this possiblity.

Only a very high alkalinity would be harmful to your fish and you won't get it that high unless you really try.

One of the best ways to increase alkalinity is to add a bit of baking soda. About 1 teaspoon per 10 gallons at first then check your readings after about an hour.

What is ideal? That depends on your fish honestly

MM

Answer 2

What kind of fish do you have? Some fish need a high alkalinity (such as African cichlids) and some need a lower alkalinity. But alkalinity does resist ph change.

The thing that disturbs me is that you are using distilled water for the fish. There are no minerals of any kind in distilled water.
http://www.thetropicaltank.co.uk/purewatr.htm
http://badmanstropicalfish.com/start_up/start_up7.html
http://fins.actwin.com/mirror/begin-chem.html
http://www.aquariumsecrets.com/sources%20of%20water.htm

BTW: where did you read that alkalinity is bad for a fish's gills and eyes? Remember distilled water does not exist in nature so fish would have to have evolved to handle alkalinity of some kind. And when a fish repirates (through the gills) CO2 leaves their bodies and CO2 and water make carbonic acid so without carbonate hardness in the water it becomes more and more acidic beside having the bacteria in the tank turn the ammonia to nitrite (which combined with water is acidic) and nitrate. Test your ph of the tank sometime. I'd bet it pretty low.

Start using treated tap water (get a good water conditioner) and research what your fish like for condtions. I have African cichlids and hard water here (great mix) but if I need to make the water harder, I add baking soda. To make water softer read the complete article on this page
http://fins.actwin.com/mirror/begin-chem.html

Answer 3

Distilled water is horrible for fish. It is way too soft, and tends to be acidic. Alkalinity, KH or carbonate hardness is only part of it. With a 0 KH your tank's pH will tend to rapidly change. (Rapid change is very bad.) There is also GH, or General hardness (magnesium and calcium). Fish need a certain amount of mineral to thrive.

The real question is what is your tap water like and what sort of fish do you have? A soft water fish like a tetra will thrive in a 5 KH, while mollies will drop like flies. A hard water with a KH of 20 would be great for a molly, but very hard on a tetra. With soft water fish I'd recommends cutting your tap water with distilled until it hits 5 KH. For most fish you'll want the 8-10 range. Try live aquaria's fish profile for various fish. Just remember that rapid change is bad even in a good direction. Make adjustments slowly.

Answer 4

First of all I will strongly suggest NOT PUTTING baking soda in your tank for any reason.

Use only "complete" buffers to reestablish the carbonate hardness. A complete buffer is one that contains more than just baking soda (sodium bicarbonate). A complete buffer needs to contain several carbonates and bicarbonates, and also needs to include borates in its make-up.

Only so-called complete buffers, the ones that contain carbonates, bicarbonates and borates will raise the alkalinity and prevent acid fall of the pH. This is most important, as some hobbyists are under the false impression that they can use plain baking soda to achieve this.

This is not so at all. You do need a complete buffer. Using only baking soda will NOT do it for you. On the contrary, it will maintain the pH at a low level, as the natural pH of baking soda (sodium bicarbonate) is only 7.6 It may raise the pH when you first add it to the water but the rise will only be temporary. Soon the pH will drop again. If you continue this treatment for a long time you will end up with a situation where your buffer is totally skewed towards bicarbonates, a pH that will drop regardless of what you try to do. To counteract this you will need to use Sodium bicarbonate
Added to this your salt levels in your tank are off the charts.

Buffering capacity determines ability to maintain a constant pH in water. Ideal level for saltwater tanks is 180 to 300 ppm and 120 to 300 ppm for fresh water.

PH is the measure of acidity or alkalinity in water. 7.0 is neutral, lower than 7.0 is acidic and higher than 7.0 is alkaline. Proper pH is perhaps the most important factor in a successful Aquarium. Correct pH ensures your fish and plants stay healthy.

You should not be using distilled water in your tank. By definition, distilled water has essentially no KH. That means that adding even a little bit of acid will change the pH significantly (stressing fish). Because of its instability, distilled (or any essentially pure water) is never used directly. Tap water or other salts must first be added to it in order to increase its GH and KH.

The best thing right now you can do for your tank is to use tap water. You need to get the GH and KH added back to your tank. DO NOT do more than a 20% change. You don't want to shock your fish with the wide PH change.

More about Buffering:

The property of water to resist changes in pH is known as buffering capacity. You can determine the capacity of your buffering system by measuring total hardness. A reading of 4-6 dH or higher is usually adequate to keep the buffering system in place and maintain a stable pH. A reading under 4 dH means there isn't enough of a buffering system and the pH is likely to drop. For higher pH levels, you will probably want to aim for 6-12 dH. Many hobbyists choose to measure only Carbonate Hardness (KH), which is a measure of the calcium carbonates in your water. This test is also effective in maintaining a proper buffer system. When testing for Carbonate Hardness, a reading of 75-100 mg/L is adequate for most aquariums, while a reading of 100-200 mg/L would be desired for higher pH levels. For the purpose of freshwater aquariums, measuring either total hardness or carbonate hardness is necessary, but measuring both independently would not be needed.

You need to know that anywhere in your aquarium where detritus (a fancy term for dirt) accumulates is a source of Phosphate production. As detritus accumulates in your gravel bed and on your filter pads, the Phosphate levels in your aquarium rise. Free Phosphate ions may bond with calcareous buffering material, precipitating calcium from your aquarium, and reducing your aquariums ability to keep pH stable. This is why it is so very important to clean your filter pads regularly and vacuum the aquarium gravel with each water change. In addition, your tap water contains buffering ions. Doing regular partial water changes will help to replenish the buffers which have been lost. This is important in all aquariums, because fish respiration and organic wastes alone will cause a gradual drop in the ability of your aquarium to buffer against pH swings.

I hope this helps.