The Cichlid Room Companion

I'm not skilled in the art of keeping fish and using forums.

So I'm not that fortunate to be buying anything that helps soften my tap water. So the big question is what are my options to lower the hardness of my water.

I know distilled water is very soft and lacks the minerals to buffer PH. It's advised to add minerals but I can't buy that. My thought is can distilled water can be added in the smallest percentage and still keep enough minerals to maintain PH?

I'm really concerned because I got a gift of a pair of triple red cockatoo dwarf cichlids. My tap water hardness is at the highest my test strips read (300 ppm) and PH sits closer to 7.8 maybe a little bigger. Research advise lower PH and softer water.

I have 4 plants and 1 drift wood I don't know how that can contribute to hardness.

Your A. cacatuoides are quite adaptable to water values. They should adapt to your hardness, but not breed or be especially healthy at that level. I would suggest that you mix 50:50 tap water with distilled/RO/DI water. The tap water will provide any buffering that is needed.

I agree with what Nike wrote, but be very carefull to avoidwater softeners.


What your average softener does, is replace Mg++ and Ca++ for Na+. due to its lesser charge, each of the replaced Mg or Ca ions is replaced by 2 Na ions.


The result is a higer count on a condutivity or TDS measurement - and that is what you should refer to.


What your fish experiences is a certain pressure - osmotic pressure if yoou want to google it - and this pressure is made op by each and every dissolved item. Replacing 1 Ca for 2 Na makes this pressure higher, where you want to lower it.


in total - only 3 techniques exist to soften water:

Distellation - very energy intensive
osmosis - creates a lot of waste water
ion exchange, where Mg, Ca, Na and all other positive ions are replaced by H+ and Cl-, SO3-- and so on are replaced by OH-. These two combine to H2O
this implies working with srong scids and bases, something no chemist would do at home.

You could try catching/collecting rain water.
Rain water is usually softer and lower pH than municipal tap water.
Gradually add the rain water when you do partial water changes.