why is rain water not good for aquaria? can i use rainwater for recirculation for catfish growing?

Answer 1

I would advise against it if you are using it for an indoor tank. Natural rainwater is slightly acidic even without pollutants. As the rain falls, it picks up carbon dioxide from the atmosphere to form varying amounts of H2CO3 - a neat little acid that buffers your water against further pH change. It will lower your pH some, but to a level your fish won't tolerate. You get the same thing with a CO2 reactor.

But rainwater will also pick up chemicals you don't want. Acid rain is caused by either sulfates (H20 + SO4 = 2H2SO4 + O2 - free oxygen and sulfuric acid!) or nitrogen oxides (usually written as NOx, because they can be NO2 or NO3 - nitric oxide and NO3 nitrate, which dissolved in water can form nitric acid). The pH, depending on where you live, can be as low as the 4-5 range - somewhere between 100 and 1,000 times as acidic as water with a pH of 7.0.

Besides the acid issue, the rainwater can pick up salt (if near the ocean), mercury, and iron. Ghapy brings up an excellent point about this - even though the water evaporates, these chemicals remain in your tank and concentrate. If you top this off with more rainwater, you're adding more pollutants as well. It's the same as keeping a saltwater fish tank - if you don't top off your water with fresh water before you do a water change, you keep increasing the salt concentration - slowly, certainly, but it's occurring.

Depending on where you live, and what's upwind of you for a few hundred miles or more, I'd even recommend doing water changes or topping off of an outdoor garden pond with tap water.

You'll have to excuse the waterchemistry lecture, but this is the reasoning behind any information you may have read or heard.

Answer 2

Rainwater is very acidic so adding rainwater to existing tank water, depending on the pH present to begin with and what fish you are keeping, could swing the pH too low. Also, nowadays, rainwater often picks up atmospheric pollutants in the air on the way down which you would be adding to your tank.

I have never used rainwater in my aquariums. However, tap water is far from pure and free of pollution and contaminants. Outdoor ponds obviously get rainwater "added" on a regular basis when it rains. I am not sure what you mean by recirculation or what catfish you are raising but most catfish are pretty tough. If you keep an eye on the pH you could probably use some rainwater.

Answer 3

I use a mix of rainwater and tap water and still use a water ager/dechlorinator as we have high chlorine levels in our tap water - my fish are fine.

Growing up in the country I always had fish and had no choice but rain water. Gradually add your fish to the tank when you bring them home - a few ml of tank water to the bag at a time over an hour or so and they will aclimatise to almost any water.

But yeah, just check the pH levels and any other test kits you might have and keep it at recommended levels and rainwater should be fine.

Answer 4

Actually there is nothing wrong with using rain water. I use it in my tanks. I do filter it however. Your PH, depending on where you live may be lower than normal only because rain water is SOFT not a hard acitic water.

Test your rain water first. You will find it testing much better than your tap water.

As far as polutants, not as many as you think. The nice thing about rain water, it doesn't contain ich!

I have two very large outside ponds that are rain water fed. All the Koi are happy there and I use no tap water in the enclosed ponds. Rain water does not contain the chemicals you think it does. The minute quantities of "chemicals" as one mentioned here are less than what is in your tap water.

Seriously, have it tested against your home water and see. I did. I was afraid of "acid rain" and other things. It was cleaner than what we were drinking out of our kitchen.

Answer 5

Rain water is fine for your aquarium. When tested, rain water is better for your skin, hair pets etc. than your tap water.

The main reason rain water isn't used in a home aquarium is due to the hardness. Most rain water is too soft and does not hold the PH required by most fish. Mind you this isn't always the case.

I use rain water all the time for my orchads, pets and tanks, not to mention the outside ponds. Test your rain water. If the hardness is 125 or better, you should have no problems.

If you are collecting it from a roof gutter, be sure to strain it to keep the debris from getting into your tank. Or let it sit and settle before using it.

Answer 6

That depends on the air pollution. If you are living in a city area most probably the air pollution will be high. So rain water will have a large amount of dissolved chemicals and acids. This will not be good for fish. So you need to use either ground water or water purified by ozone or chlorine.

Answer 7

Besides the things that pollution in it, rain water will have no buffering capacity so anything such as peat, driftwood, etc. that would tend to lower pH will have a much stronger effect on your water parameters. That's basically the same reason it isn't good to use bottled water off the shelf in the store.

Answer 8

Of course, pollution is certainly a valid reason why to avoid rain water, but even those who live in an area with perfect rain water shouldn't use it.

Rain water is evaporated water. When water evaporates, all of the salts and minerals and vitamins in it remains behind, and the result is water which is lacking in many nutrients fish need for long term health. It also lacks any buffering capabilities and can result in unstable PH. Since tap water already has most of these elements in it, and because tap water is already buffered (acid water rusts pipes) it's much more suitable for fish, once the chlorine has been taken care of.

Answer 9

relies upon on the length of the aquarium , yet no longer fairly. catfish strengthen till the day they die, regardless of what there in.. even dirt. if it really is an excellent small tank.. then you definitely could in person-friendly words have one catfish.. and practice to get higher and larger tanks. yay

Answer 10

Rainwater carries all sorts of nasty goodies with it, but most fish can be acclimated to it.