Using Rain Water In My Aquarium

[Joller]

Well its been raining a bit here so i put a big bucket under a downpipe and filled it up
the pH is the same as my tap water that i usually do water changes with

would using fresh rainwater in my aquarium be better for my fish than tap water(with added water conditioner for the fish)

 

[fatheadminnow]

Form my understanding you wouldn't want to do pure rain water, you would want to mix it with tap water.

It is also very important that you do not live by a city or any places that has a lot of pollution in the air, which can get into the rain water and harm the fish.

Rain water will lack in trace minerals found in tap water which are good for the fish, so that is another reason why you would want to mix it.

Rain water will also have no trace of ammonia, nitrite, nitrate, chlorine or any heavy metals which makes is a very good source of water to use.

There are quite a bit of topics on here about using rain water, with a quick search you could probably find some.

Other than that, someone here with a little more experience than me will most likely come on and give you some more advice.

-FHM

 

[Joller]

Thanks, I'll use tap water seeing as it doesnt show any level of ammonia or nitrates/nitrites
I live in an urban area of a small 'city' on the east coast of australia.
I figured that if the fishes natural environment was rivers in rainforests(south american cichlids) then rain water must be best for them.

 

[waterdrop]

Yes, there was a really excellent post recently (was it OM47?) on... if I remember... using rainwater to mix in with tapwater to make a lower pH water to mix with high-pH tap water and bring it down.

One of nice tricks was to wait for a really heavy downpour. What you do is get ready when the downpour starts and let it go for a while, washing the dust and other nasty particles off the roof and out of the gutter, whatever, then after a bit you fill your buckets and the resulting rainwater will often be nice and pure and lower pH, but you should test this with your good liquid-based test kits.

As FHM says, you never/rarely would want to use this pure, you'd be using it to make up a mix with tap water. It should be tested after mixing too.

Its good to think of all the positive stuff coming in with tap water, especially the calcium, magnesium and and other trace minerals coming in in smaller quantities. The fish need and expect these to match up with what they're used to. The live plants need these nutritents coming in.. in fact, water changes of tap water can be thought of as a nice source of some of the nutritents plants need, although not necessarily enough of them.

And of course, as FHM points out, all of this is only necessary if you have a need based on a "pH or hardness problem" (typically) and depending also on your type of tank, type of fish and goals for the setup you're maintaining.

~~waterdrop~~

 

[OldMan47]

It sounds like something I might have said WD. I do measure my rain water and find that after a good flush it is almost pure water. That makes it unsuitable as a straight water to add to a tank because, as you noted, the fish need some minerals in their water. They also need some KH to their water but my tap is so high that a mix works out well for the softer water tank that I maintain. The rest of my tanks still get straight tap water.