hard water treatment advice please...

[fisher]

Hello. My well water is very hard. When I top off my tank it causes ph shifts and kills my fish . I lost 6 fish before I figured this out. Thankfully I figured it out before I "murdered" anymore of the poor things! I've actually been keeping fish for several years- very successfully I might add. I recently moved and encountered this hard water issue. When I figured out what was happening, I added some aquarium salt to my tank and, needless to say, have not topped off my tank lately. A week ago was when I figured out the problem and nobody has died since then. (Fingers crossed.) Anyway, I'm pretty certain this is the cause of death for those 6 fish. Here's my issue - Obviously, I'm going to need to add water (for top off soon, and eventually cleaning) and I was wondering what I should do to the water before I add it? Use aquarium salt? If so, how much? Or some other product? I live out in the boonies and have a toddler - I can't realistically purchase water on a regular basis for my tank. I need to be able to treat the water w/ some sort of product or salt/what?? - that I can keep on hand. The fish I have are --- 5 white clouds, 3 catfish, 6 kuli loaches. Once I get this hard water situation under control, I want to add one betta and a few more white clouds (those are the ones I lost). Thanks so much for any help out there - and for reading to my long-winded post.

[TomK2]

I am trying to understand why your tank, after being filled with tap water, would change in pH dramatically, thereby allowing a water change to cause a shift. Can you be more specific, ie: what the pH and hardness levels are? For both tap (after sitting out overnight) and tank?

I have never bothered to try and reduce water hardness in the past. Water softeners exchange salt for other ions to reduce hardness. Not sure if reverse osmosis or deionized water would be of benefit. You could mix distilled water with tap water too dilute it out. Hard water is usually high in carbonate, which tends to buffer the pH up higher and keep it rather stable. So I am confused.

[Jchillin]

I am also intrigued by this. Top off water should not be able to shift the ph so dramatically, especially if coming from the same source.

In line with Tomk2's thoughts, do you know where your water originates and if possible, get a water test result from them? Of course if you are using well water, that may have a lot to do with it.

[An t-iasg]

I also am intrigued! Can you provide pH, KH, and GH test results, with water that has been sitting out overnight? I suppose it is possible to have a high GH (the "hardness" factor) but a low KH (for pH stability), but that would be out of the ordinary.

What size tank do you have? I am taking a guess that your bioload is a bit high for the tank size, and the pH is dropping through the week (the acidity of the ammonia given off by many fish is lowering the pH) and then at topoff time, you are raising the pH with the new, hard water. Hmmm...just a guess...

What are you using for substrate? It may be helpful to also to repeat the tests with a glass of water that has some substrate in the bottom. Let it sit out overnight and then test GH, KH, and pH.

[fisher]

My tank is 29 gallons and I use well water. I have a gravel bottom, hang off the side filter and lots of hornwort floating in my tank, and currently 15 fish reside in it. This has always worked for me (for about 7 yrs now, until I moved and started using the well water). When my fish died a week and a half ago, I tested everything - ph, ammonia, etc. - all normal. GH was very very high and Kh was not so good. Honestly, I didn't understand the Kh results. What I did gather, from reading the pamphlet that came w/ the kit, is that when one has very hard water and all these ions are produced, then when topped off w/ more hard water, this (does something this lay person doesn't understand w/ the ions) and makes the ph shoot up, thus killiing the fish. Sorry, I don't have the numbers from those tests, nor do I remember them exactly, but I'll test again (w/ substrate in the bottom, let sit out overnight). In a couple days I will post another update w/ the new readings. Thanks to all three of you for your interest and help.

[An t-iasg]

How many gallons do you need to top off? Is your pH rising or falling after a topoff? I have found that my GH reading will increase by one degree through the week, as evaporation of the water causes the minerals to stay behind. So then the water that I'm using for a water change is one degree less hard than what's in the tank. This has not caused any problems for me, and I don't top off through the week. If you're having to top off a great deal, it may be a problem, as you are seeing.

The GH test kit measures calcium and magnesium. There may be other minerals in your well water that are affecting the hardness and not showing up in the GH test. KH is a measure of the carbonate hardness, and this factor is what stabilizes the pH. If you have a low KH, you're more likely to get pH swings.

Say your GH rises thoughout the week due to a lot of evaporation. Adding water with a slightly lower GH from your well shouldn't really do anything that drastic...It would be interesting to take a KH reading from your well water and then a tank KH reading, right before a water change or topoff, and then right after. I have discovered that my KH was at 3 initially, but by water change time at the end of the week, the KH was 1 and the pH pretty much crashed, down to 6.2. I used buffer to stabilize my KH. I consider my GH to be "hard", but adding buffer doesn't affect the GH. You may need to add some buffer once we figure out what is going on with your parameters.

What were the ammonia and pH reading of the tank water? And then also the pH of the water that sat out alone and in a cup with substrate - I know this is a lot of testing, but it's what I did to figure all this stuff out in my tank, and I'm trying to follow that same train of thought to see what's going on with your tank. The reason for doing a test with and without substrate in the cup is to see if the substrate in any way is responsible for the pH shifting. If it is, you should go with a more neutral substrate. I have used both major brands of gravel, Estes and SpectaStone, with no trouble at all on my parameters.