George07

[George07]

I have one 40 gallon breeder. It's a planted tank and because of the good advice i got here last week i have decided to keep only my Cardinal Tetras, my Cory cats and two Angelfish that get along. I have been wanting to look into a water changing system for some time and to possibly stop the filtered water from Walmart. Do you think it's okay for me to use distilled water for my water changes?

 

[Lajos_Detari]

If you use distilled water, probably you may need to add some minerals(GH+ salt).
Distilled water has zero mineral and a GH of 0.

If your tap water is soft enough(GH 2-10) - rough estimation), you can just use your tap water.
Then you don't need to waste money on distilled water.

According to this website, Angel fish can live in a GH of 0-15.
Probably you can aim for a GH somewhere in the middle (5-7) so as not to have extreme condition.

Pterophyllum “scalare” – Angelfish — Seriously Fish

www.seriouslyfish.com

 

[George07]

I make my own distilled water and only started using Walmart water when i was told that distilled water was not good for tropical fish. I fail to see why distilled water would not be good for my fish

 

[Sunnyspots]

I make my own distilled water and only started using Walmart water when i was told that distilled water was not good for tropical fish. I fail to see why distilled water would not be good for my fish

I think it has to do with the loss of minerals that happens when water is distilled. Fish need all sorts of minerals in various amounts e.g. calcium, but none pass over with the water during distillation.

 

[George07]

I know, and these same minerals stay in the aquarium after the pure water is evaporated out.

 

[Sgooosh]

I know, and these same minerals stay in the aquarium after the pure water is evaporated out.

Think about this then: no fish live in pure water
Plus how much nutrients does distilled water have anyway

 

[Sunnyspots]

I know, and these same minerals stay in the aquarium after the pure water is evaporated out.

True. I top up with pure water, but I do water changes with dechlorinated tap water.

 

[George07]

Think about this then: no fish live in pure water
Plus how much nutrients does distilled water have anyway

I'm sure that you are right about distilled water being bad for our fresh water aquariums, but it doesn't make sense to me because only pure water is evaporated out and should be replaced with only pure water or distilled water. I just want to be understood here...

 

[George07]

True. I top up with pure water, but I do water changes with dechlorinated tap water.

I have been using distilled water from home and RO water from Walmart. I want to look into using dechlorinated tap water and need to check my local water chemistry.

 

[Essjay]

It is better to use a form of pure water for topping up between water changes - distilled, DI, RO or even rainwater of there's no air pollution. As you say, only pure water evaporates so it needs to be replaced with pure water.

But most fish need some minerals in the water. Soft water fish only need a small amount while hard water fish need a lot. If the tank is filled with pure water, it is usual to add some minerals in the form of remineralisation salts; the amount of these salts depends on the type of fish. Water changes are then done with pure water plus remineralisation salts mixed in a container before adding to the tank so the new water has the same mineral content as the tank water. Top ups between water changes are done with pure water only.