RO system to remove sodium from softened water

Hey all,

I have a whole home water softener installed, and it softens all the water in my house, even the outside faucets. I took a reading at every faucet, inside and outside, with a hydrometer, and the salinity was ~1.004 at all of them.

I have 2 tanks in my house, a 10 gallon with a single male betta, and a 29 gallon that had 6 zebra danios and 4 white skirt tetras. Keyword had :-(

The 10 gallon was cycled before getting the betta, and the 29 gallon was my first tank (and I struggled with crashing the cycle). The 29 gallon eventually stabilized, I did frequent water changes (at least every other day), with temperature matched water and very close pH. Once stabilized, the tank was always at ~7.6 pH, 0 ammonia, 0 nitrites, and ~10 nitrates (my tap water has about 5ppm nitrates). I kept up with weekly partial water changes and the occasional gravel vacuuming, but after several weeks the danios started getting lethargic and rapidly died off. The tetras were struggling quite a bit after that, having trouble swimming and not eating. I made the tough decision to euthanize them because they were obviously suffering horribly. (I didn't have any clove oil, so I put them in a bowl of tank water mixed with baking soda.)

I'm rambling now, but I guess the point of my post is that I didn't realize the amount of sodium added via my water softener was enough to potentially affect the fish. I have no idea if the sodium content is one of the factors that lead to their early demise, but I figure if I'm going to have freshwater tanks, I should eliminate all the sodium. I know I could do potassium in my softener instead of sodium, but I'd like to try an RO solution to have more precise control over the water. The price isn't so much a concern, but I'd like a system I could attach to a faucet as needed, vs having one permanently installed somewhere. Just about every system I've researched comes with its own faucet and is meant to be installed on the water line somewhere in the house. I'd rather not add something like that if I could avoid it, but I realize most of these systems are designed to be used for drinking water.

All that said, does anybody have any recommendations?

Thanks!
benlacy2112

 

there's usually a bypass valve on or before the water softener.

most fish, especially if captive bred, can adapt to hard water.

 

I should've mentioned I'm not too interested in bypassing the softener. It's in an annoying spot and it would be just the cold water anyway. A portable (i.e. just attach to the faucet when I need I) RO system is all I'm really wondering about. No permanent hookups, ideally no faucet included. That's the ideal solution for my situation I think.

 

I'm in the same boat as you, what did you end up doing?

 

Hi, did you use a salinity hydrometer? Or a general hydrometer that measures the specific gravity? Because generally whole house water softeners are low in sodium and safe even for people on low sodium diets. Yeah the softener replaces calcium ions with sodium ions but the salt itself is washed away during a recharge and rinse. I have only used softened water for years with no issues. My bypass is really tough to get by also.

Hard water is often high or very high TDS total dissolved solids and that number doesn’t change with a water softener as one ion is exchanged for another.

But one thing I should mention is that though KH/Alkalinity stay the same with softened water, GH is now 0. If you are not replenishing those minerals with something like Seachem Replenish and Seachem Fresh Trace I can see that your fish would potentially get sick and die or be weakened. Without those minerals their osmosis would also be weakened. Even soft water fish need some minerals to a GH of 2 or 3 degrees.

I can’t recommend an RO system but I don’t really think you need one if you replenish the minerals in the water. If you do end up getting an RO system make sure you use the two I mentioned above and also Seachem alkaline buffer as the RO water will be low in KH.

Lastly, I would highly recommend treating any new fish to a new tank with Prazi Pro as many fish come home to you with parasites, flukes and this gets rid of them. Treat the whole tank. Doesn’t hurt the cycle.