any and all of your live bearers will work, especially mollies.

Your water doesnt matter so much since there are simple tricks to change and keep the water PH soft or hard. It is more a matter of keeping it at the same level.

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.

Now the question becomes what to do if the fish you want to keep have very special pH requirements. If your fish prefer a pH level which is reasonably close to the pH your aquarium water is naturally buffered to, then I do not recommend you make any changes at all. Unless you are keeping an extremely specialized fish your fish will be fine. On the other hand, if your fish have pH requirements which are far from the values in your tank, then you have work to do.

Let us consider methods of raising the pH of your tap water. There are many additives on the market today which claim to raise your pH. Most of the liquid products on the market today are a 50/50 success at best when used alone only to find the ph will soon return to the normal level of 6. You also need to use a product to increase the buffering ability of your aquarium. To maintain a stable pH in the upper levels of the pH scale for fishkeeping, I would recommend using a buffering substrate such as crushed coral. You can add crushed coral to your existing aquarium. You can place larger amounts of shells or chrushed coral beneath the substraight in the tank. I personally place the crushed coral in a mesh bag and place the bag in my filter. You will want about 1 kg of crushed coral per 40 liters of water to buffer the water to hold a pH around 7.6. This method does not allow for the use of large quantities of crushed coral, but can be effective if you only need to make small adjustments to your aquariums buffering ability. This is why ocean items such as shells and ocean sand should not be used in a fresh water aquarium. It does raise the PH level.

Be assured that attempting to control pH is the most frustrating experience for a fish hobbyist. I would guess that 50% of the problems encountered in new aquariums are a result of the aquarist attempting to change the pH level. Few fish keepers actually need to adjust their pH. For the majority of aquarists your tap water pH will be adequate. The dangers of adjusting the pH incorrectly far outweigh any benefit you may receive by moving your pH a few points on the scale.

Remember, when it comes to adjusting your pH, less is more! Stability is most important. Routine maintenance is the key to keeping your pH stable and your fish healthy!

Also, do not use baking soda in your tank. Over doing the ph plus adding additional salt is not going to do your tank any good. It will also revert back to 6 when the carbon filters pull the Soda out.
Hope this helps

If you have hard, alkaline water you could try rift lake cichilds. You’d want your pH to be 7.8 or above though… Malawi’s like it in the 8.0 range and Tanganyikans like high 8 to low 9 pH (those are the names of the lakes they come from, btw) Cichlids are mouth brooders and although they are generally easy to breed (some species) they are aggressive and need larger tanks (at least 30 gallons if you’re not doing shell-dwellers) and special consideration needs to be taken in setting up their tank. They come from a rocky environment and need lots of places to hide. Especially from aggressive males. Don’t know if this was more than you were looking for, but goodluck!

Almost any of the other livebearing fishes will work,this sort of water is ideal. Danios,Paradise fish,Bettas,some of the Riverine Central and South American Cichlids. Even Angelfish,although they a supposedly soft water fish,they are so many generations removed from the wild, that they will spawn in your sort of water.

I have off the charts hard water in both of my tanks.
I have a 35 gallon tank with Bala Sharks, Silver tip Sharks, a pleco and ghost shrimp. In my 10 gallon tank I have Mollies and a pleco.

The mollys breed like crazy and have a lot of babies. they are so much fun to watch and can handle the hard water. I do add salt, water conditioner, start right to my tanks and it brings the hardness down but it is still in the stress range.

I also do a water change at least 1x a week and I am always watching it and adding stuff when needed.

Check out and read up on the mollys and other fish there

you know what…i was JUST reading about hard and soft water cause i REALLY want a planted 55 gallon tank with breeding german blue rams in it but i heard they need soft water and i have hard water. then i was looking up people who sell them and breed them and they said the fish have been raised in hard water and have never even been if softer water. he said “so only the strong survive”. and i also heard you can slowly get them used to hard water. not sure if this helps but yea! just thought i’d tell ya that.
Hard Water – is water that contains many minerals, such as calcium and magnesium. When you have hard water (use a test kit) it can be more difficult to regulate the aquarium pH. Reverse Osmosis filters can soften hard water.

While I have not heard about metals changing the ph of water there are many factors that can cause the PH to be either high or low. The water you are using to start with. In short the acid levels are known as the PH level in your tank. Here is more on PH how it works and how to keep it stabe.

This is going to sound dumb but what kind of gravel do you have? Believe it or not certain types of gravel will keep your ph from increasing or increase it too much.

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.

Now the question becomes what to do if the fish you want to keep have very special pH requirements. If your fish prefer a pH level which is reasonably close to the pH your aquarium water is naturally buffered to, then I do not recommend you make any changes at all. Unless you are keeping an extremely specialized fish your fish will be fine. On the other hand, if your fish have pH requirements which are far from the values in your tank, then you have work to do.

Let us consider methods of raising the pH of your tap water. There are many additives on the market today which claim to raise your pH. Most of the liquid products on the market today are a 50/50 success at best when used alone only to find the ph will soon return to the normal level of 6. You also need to use a product to increase the buffering ability of your aquarium. To maintain a stable pH in the upper levels of the pH scale for fishkeeping, I would recommend using a buffering substrate such as crushed coral. You can add crushed coral to your existing aquarium. You can place larger amounts of shells or chrushed coral beneath the substraight in the tank. I personally place the crushed coral in a mesh bag and place the bag in my filter. You will want about 1 kg of crushed coral per 40 liters of water to buffer the water to hold a pH around 7.6. This method does not allow for the use of large quantities of crushed coral, but can be effective if you only need to make small adjustments to your aquariums buffering ability. This is why ocean items such as shells and ocean sand should not be used in a fresh water aquarium. It does raise the PH level.

Be assured that attempting to control pH is the most frustrating experience for a fish hobbyist. I would guess that 50% of the problems encountered in new aquariums are a result of the aquarist attempting to change the pH level. Few fish keepers actually need to adjust their pH. For the majority of aquarists your tap water pH will be adequate. The dangers of adjusting the pH incorrectly far outweigh any benefit you may receive by moving your pH a few points on the scale.

Remember, when it comes to adjusting your pH, less is more! Stability is most important. Routine maintenance is the key to keeping your pH stable and your fish healthy!

Also, do not use baking soda in your tank. Over doing the ph plus adding additional salt is not going to do your tank any good. It will also revert back to 6 when the carbon filters pull the Soda out.
Hope this helps

Bettas are very hardy, I have several and have even included them tanks with my regular fish. They breed very interesting too.

Not bettas.

A pH of 7.0 is neutral, which means the number of hydrogen ions and the number of hydroxide ions are balanced. If you have more hydrogen ions, the water will be more acidic (a lower pH). If you have more hydroxide ions, the water will be more basic (higher pH). Also, buffers (alkaline earth metals and alkali metals) will make it more difficult to alter the pH, though they do not directly raise the pH themselves.

The acidity or basicity you need depends on your fish… Most are tank raised (unless you have wild fish), and are VERY adaptable, often having been raised in city tap water with a pH above 7.5, however wild fish and any of the more delicate species will require a more specific pH.

The main cause of a fluctuating pH in an aquarium is a low buffer– if your tap water is very soft, nothing will prevent the pH from swinging. For this reason, it is good to have a reasonable amount of hardness; you do NOT want your pH to shift. As long as you avoid pH adjusting chemicals, you shouldn’t have an issue with pH.

Radio Shack recycles batteries, but when I took them there, they told me it was perfectly safe to throw regular alkaline batteries away now.