Water Softener Woes

By Tom Lang

We have been seeing more and more homes installing water softeners and then having problems with their aquariums. In order to soften a home’s tap water, many water softeners work by exchanging minerals (mostly calcium and magnesium) with sodium. While this is good for your pipes, shower doors and washing machines, it’s not great for fish.

Aquarium water needs to contain a balance of electrolytes (solutes that break down into ions when dissolved in water) in order for fish to be able to regulate their internal homeostasis. Freshwater fish, especially, require some calcium and magnesium as well as carbonates and other minerals in their water for this osmoregulation since they continuously absorb water into their bodies though their skin and flush it out through dilute urine produced by their efficient kidneys. Electrolytes are lost from the body during urination and if these same ions are not present in the surrounding water, then the fish is unable to achieve internal electrolyte balance rapidly leading to death.

So it is not so much the presence of sodium that causes fish problems in softened water, but rather it’s the lack of calcium and magnesium (measured as GH – general hardness) and carbonates (KH – carbonate hardness or alkalinity) that fish need to survive in an aqueous environment.

In a freshwater planted aquarium, a balance of minerals is also important, however it is interesting to note that plants may do fine for quite a while in softened water even as the fish perish. This is due to a hydrophyte’s (fully submerged aquatic plant) ability to retain minerals in its tissues since, unlike terrestrial plants, it does not need to expend energy retaining water. Calcium and magnesium are considered “secondary” nutrients because plants require these in smaller concentrations than nitrogen, phosphorus, and potassium. Often, aquarists with planted tanks will also add plant nutrients that contain enough calcium, magnesium and other minerals for the plants, but not in enough quantity to provide for the far greater needs of the fish.

Finally, using softened water in a saltwater fish or reef aquarium creates other issues. Again, the lack of calcium and magnesium may require supplementation to bring them back into line with natural seawater. While saltwater fish are drinking seawater rather than absorbing it through their skin like freshwater fish, they still must regulate their internal electrolyte balance. It is necessary to add calcium, magnesium and carbonates to artificial saltwater made with softened water if tests indicate levels below natural seawater.

Summer to Winter in Fresno

By Aletha Lang

An aquarium heater should be considered a critical piece of equipment for your aquarium, just like a filter that is essential to the lives of your tank inhabitants.

As we who live in Fresno and in the San Joaquin Valley well know, our seasonal temperatures vary from summers at 105 degrees Fahrenheit or more to winter temperatures as low as 32 degrees. So winter is a great time to check your heater to be sure it is operating as you expect it to. Heaters do go bad and rather than assuming yours is working because the light’s on or because its dial is set at the right temperature, be sure to verify that it’s working properly by checking the actual temperature of your aquarium water with a trusted thermometer. Tropical fish (both freshwater and saltwater) require water temperatures to remain very stable in order to survive. A narrow range from 77 to 82 degrees is ideal for most.

Perhaps you’re already aware of the stresses extreme temperature swings can cause your fish: parasitic outbreaks, lethargy, uneaten fish food sitting on the bottom of the tank. The latter is not a direct, but rather an indirect result of the fish not feeding normally in cold water, and we all know that rotting food leads to degrading water quality.

So before you lose any fish, check your heater today. And please contact us if you need a replacement!