"Runaway" hardness and water softeners

[tommy_vercetti]

Hi,

I have a couple of questions regarding water hardness. We have well water which is very hard (400 TDS.) I don't use an RO filter for my makeup water--instead I try to choose fish which can tolerate hardwater. We have a water softener for the house, but I use water which has not passed through the softener for my aquariums.

1. I am concerned about "runaway" water hardness over time caused by evaporation. If I never use water with a lower TDS for water changes and evaporation top-off, won't my TDS slowly rise over time? I do frequent large water changes on my system, which dilute the nutrients and dissolved mineral buildup; but since there will always be evaporation then slowly I will see an increase in TDS, right? Is there anyway to counteract this? Maybe doing an occasional 90% water change will bring the TDS back down to near 400. So far I haven't seen this increase in TDS, but I am thinking about the future. I've only been up and running at the new house for a month.

2. Many aquarists recommend adding salt to their aquariums for disease control. Water softeners replace minerals with salt. With this being said, can I use water which has been through my softener in my system? I've heard that I shouldn't do this but never knew the reason. I guess you would have a buildup of salt over time, is that it?

 

[mgamer20o0]

1 doing water changes will stop this liek you hinted at. mine are higher then that. i do weekly 50% water change.

2 really.... not many do..... many people who dont understand what they are doing add salt. i believe water softeners that use salt isnt very good to use on the tank. just use the well water.

 

[mudraker]

Consistent clean water in the tank will keep most pathonogens at bay, and water softeners (mostly are sodium based) can have worse effects in the long run.

Salt mostly cures problems that would not exist if the water were kept fresh and clean in the first place.

Keep your water fresh, QT new fish, watch and research what you put into your tank .

Your fish will thank you for it.

PS. My water is from a well that is ridiculously soft out of the tap with very low acid.

 

[strokinbyeu]

the water you get from the tap with a water softner nerver touches the salt, it souldnt contain any salt. the water is softend by ion transfers. the minerals collect on plates and when it regenerats the plates or washed off, then the salt brine is flushed thru the plates to re charge the plates, then new un treated water is fed back in to the tank to begine the softening.

 

[strokinbyeu]

the water you see in ur salt bin isnt what runs thru you water lines

 

[fan4guppy]

I would have to agree that frequent water changes with all aquarium setups.

I used to live in an area of Canada that had very hard water ... with a very high ph which was great for African Cichlids then my parents at that time bought a water softener system but I by passed that because it was on the HOT water tap and not on Cold. I would have to heat my water for water changes but!

There is something that you are not telling us as to the species of fish that you keep and or want to keep?

African Cichlids and Livebearers do very well in hard water

Tetras, Killifish and Discus prefer Soft water.

What is your desire for the fish that you want to keep.

2) Salt for tanks (non iodized salt) is recommended for aquarium use ... and is usually disolved in the aquarium as someone mentioned the water in water softeners is softened by Ions and not the actual salt ...

 

[tommy_vercetti]

In this area most of the fish at the LFS are adapted to harder water (it's very common to have hard water here.) So now I just have some angels, livebearers, corys, plecos, giant danio, convicts, and a large arowana. The arowana is by himself in a 180g, but I am looking to get a bigger tank. I rescued him off of craigslist free, and he came out of a tank with a super high tds of 800! I think they were just topping off with hard water and not doing water changes. He seems to be adjusting well to the relatively softer water (400 tds.) I use RO water for topoff, but well water for water changes.

So you'all think I ought to skip the water which goes through the softener; and do regular massive water changes with well water, right?

And you think I will be ok using well water to top off for evaporation; as long as I do regular large water changes to keep hardness in check, correct?

Thanks,
s

 

[jsoong]

An ion-exchange softener exchanges the Na (or K) in the softenen salt for the Ca & Mg in hard water. Because of valancy (charge of the ions) it takes 2 Na or 2 K to exchange for 1 Ca or 1 Mg. So basically, after softening in that type of softener, the TDS is INCREASED. So it is best to use your water before the softener for your tanks.

Aquarium salt is NaCl. It is the Cl that is most biologically active. Your softener does not add the Cl, so it is NOT the same as you adding salt. However, the purported benefit of small amount of aquarium salt as a tonic (as opposed to measured salt concentration to treat diseases) is to decrease the osmotic stress of the fish by providing some TDS (or osmolarity). This may be useful in very soft water with little TDS (although that is debated), it makes no sense to add salt to a system with high TDS to start.

It is true that evaporation will remove pure water, so the TDS will gradually increase if you only top-off with high TDS water. In theory, you are supposed to top off only using pure water (ie R/O or distilled). This is what SW folks do to prevent salt creep. Freshies don't tend to do that, as our fish can stand a bit of TDS variation. As long as you do a largish pwc from time to time to reset your tank, your TDS don't go up too far. <The amount needed depends on your evaporation. If your evaporation is 10% of the tank a week, and you do 25% pwc weekly, the max increase in TDS would be in the order of 150% of your start TDS. Many planted tank folks do weekly 50% change, this guaranteed that the added fertilizers (or other salts) never exceed double the concentration added. So if you are topping up a 10% evaporation a week, the TDS will never exceed 120% of the start value.>

 

[tommy_vercetti]

An ion-exchange softener exchanges the Na (or K) in the softenen salt for the Ca & Mg in hard water. Because of valancy (charge of the ions) it takes 2 Na or 2 K to exchange for 1 Ca or 1 Mg. So basically, after softening in that type of softener, the TDS is INCREASED. So it is best to use your water before the softener for your tanks.

Aquarium salt is NaCl. It is the Cl that is most biologically active. Your softener does not add the Cl, so it is NOT the same as you adding salt. However, the purported benefit of small amount of aquarium salt as a tonic (as opposed to measured salt concentration to treat diseases) is to decrease the osmotic stress of the fish by providing some TDS (or osmolarity). This may be useful in very soft water with little TDS (although that is debated), it makes no sense to add salt to a system with high TDS to start.

It is true that evaporation will remove pure water, so the TDS will gradually increase if you only top-off with high TDS water. In theory, you are supposed to top off only using pure water (ie R/O or distilled). This is what SW folks do to prevent salt creep. Freshies don't tend to do that, as our fish can stand a bit of TDS variation. As long as you do a largish pwc from time to time to reset your tank, your TDS don't go up too far. <The amount needed depends on your evaporation. If your evaporation is 10% of the tank a week, and you do 25% pwc weekly, the max increase in TDS would be in the order of 150% of your start TDS. Many planted tank folks do weekly 50% change, this guaranteed that the added fertilizers (or other salts) never exceed double the concentration added. So if you are topping up a 10% evaporation a week, the TDS will never exceed 120% of the start value.>

This is very useful. Thanks!
How about discus? I've heard that you can display discus (but not breed them) in hard water, particularly if you buy them from a dealer who raises them in hard water. Is this true? I would do regular large water changes and keep temperature high. Could I do it with well water at 400TDS?

 

[jsoong]

There are folks in the forum that keep discus in hard water. As long as they are properly acclimatized, they should so fine, but not breed. My lfs has their discus in plain tap, with our GH of 200+, without any apparent ill effects.