Is Water Softener Killing my Fish?

[Proteus55]

I've read a lot of conflicting opinions about this. Here in FL, many homes have all-faucet type water softeners, mostly salt-based. I had seven platys doing very well for a month and then had a sudden die-off (water chems were fine per the Master test kit, water always treated with Prime); I have been doing 30% weekly water changes with softened water, dosing the tank with Prime first. Could this have caused such a catastrophe? Could it have interrupted or ruined the cycling process, as I never really got nitrate readings despite 0 mmonia levels). I have a bypass valve, but its a pain in the rear to use, especially when I'm trying to keep the temps similar. Any first-hand users of softened water for their tanks? Thanks!

 

[mrvincent]

What's the KH&GH of the softened water ?

 

[Proteus55]

What's the KH&GH of the softened water ?

The PH is 7.2. I don't have a hardness test.

 

[mrvincent]

The PH is 7.2. I don't have a hardness test.

When KH flukes, fish don't like that, GH too. KH flukes do PH flukes too.

You must have at least 2 dKH° in your new water.

If there's 0 dGH° some fish may not be happy.

 

[Old Scales]

Yes, most livebearers like a harder water and higher pH than egglayers. Your natural water may be fine for them. Definitely check your KH. OS.

 

[threnjen]

For fish, “soft” water means water with low TDS (Total Dissolved Solids). But it’s important to note that a test like the gH test is only testing for certain things in the water, namely calcium and magnesium, that are part of “general hardness”. These are the elements that make water “hard” by standard definitions, but they don’t include all possible dissolved solids. So it’s not really a full picture of your water’s TDS. Your water could test very “soft” on a gH test because it doesn’t have much calcium or magnesium, but be very high in TDS because it has lots of sodium, phosphates, potassium, fertilizer runoff, etc.

For our use drinking/bathing/etc when we consider water hard when it has a lot of the “general hardness” minerals that make it unpleasant like magnesium and calcium. To make water “softer” for drinking/home use, we use minerals that actually make the water have HIGHER TDS. If you are running a water softener in your house, what it actually does is swap out the magnesium and calcium for sodium and it does this at a rate of TWO ions of sodium per ion of magnesium or calcium. So this means a “water softener” is actually producing water with almost 2X the TDS of the water that goes in! This means this water is usually WORSE for your fish than the water from your tap.

Also, your water softener is taking out the gH and kH from your source water (and replacing it with sodium), so generally it is replacing "good" things for fish with "bad" things for fish. Calcium and Magnesium are good to have in your tank especially if it is planted.
Now if the hardness of your source water is super high, your only real bet to resolve this is RODI water. But most fish can handle the water you acclimate them to.
You could also pick up a TDS meter to see a real demonstration of the ion exchange process I'm describing: http://www.amazon.com/HM-Digital-TD...UTF8&qid=1395261383&sr=8-1&keywords=tds+meter
Check source water softened, and through bypass. I would expect a lower TDS from bypass.

My strong recommendation: skip the water softener.

 

[Proteus55]

For fish, “soft” water means water with low TDS (Total Dissolved Solids). But it’s important to note that a test like the gH test is only testing for certain things in the water, namely calcium and magnesium, that are part of “general hardness”. These are the elements that make water “hard” by standard definitions, but they don’t include all possible dissolved solids. So it’s not really a full picture of your water’s TDS. Your water could test very “soft” on a gH test because it doesn’t have much calcium or magnesium, but be very high in TDS because it has lots of sodium, phosphates, potassium, fertilizer runoff, etc.

For our use drinking/bathing/etc when we consider water hard when it has a lot of the “general hardness” minerals that make it unpleasant like magnesium and calcium. To make water “softer” for drinking/home use, we use minerals that actually make the water have HIGHER TDS. If you are running a water softener in your house, what it actually does is swap out the magnesium and calcium for sodium and it does this at a rate of TWO ions of sodium per ion of magnesium or calcium. So this means a “water softener” is actually producing water with almost 2X the TDS of the water that goes in! This means this water is usually WORSE for your fish than the water from your tap.

Also, your water softener is taking out the gH and kH from your source water (and replacing it with sodium), so generally it is replacing "good" things for fish with "bad" things for fish. Calcium and Magnesium are good to have in your tank especially if it is planted.
Now if the hardness of your source water is super high, your only real bet to resolve this is RODI water. But most fish can handle the water you acclimate them to.
You could also pick up a TDS meter to see a real demonstration of the ion exchange process I'm describing: http://www.amazon.com/HM-Digital-TD...UTF8&qid=1395261383&sr=8-1&keywords=tds+meter
Check source water softened, and through bypass. I would expect a lower TDS from bypass.

My strong recommendation: skip the water softener.

Thanks for the solid advice and time it took to post it. I know from a neighboring forum that you are always generous with your experience and insights. I will do as you suggest and hope to report positively to anyone else in need.

 

[threnjen]

Oh, sure! I'm surprised you recognize me from that forum; I don't say too much there since they have a good team of "expert" helpers.

I kind of realized that although I hit you with a big explanation on water softeners, that didn't really answer your initial question all that well. I'm not sure that the softened water would cause the die-off you mentioned - but maybe. Platys are just fish well equipped to handle a high TDS so they wouldn't be the first fish I'd expect to find ailing from water with a really high sodium content (after all, you read about how livebearers love salted water which is very high TDS). If we were talking tetras or something, then I could easily see your high TDS water causing them a lot of stress.

So I feel like I said a lot but also said very little, because I'm not really sure that your source water has anything to do with the problem. BUT I still think you should avoid the water softener for the other reasons I mentioned, since trading calcium/magnesium for 2x sodium is really a bum deal any way you shake it.