RO/DI water?

[steve5520]

I will finally be getting a RO/DI filter in the next week or so. Having two saltwater tanks, I finally decided to bite the bullet and start using clean water.

I also have two Freshwater tanks (30gal each). Is there any real benefit to using RO/DI water in these tanks? From what I understand, I would have to add some stuff to the filtered water before use. I guess RO/DI water is an extreme low pH.

Any comments or help would be greatly appreciated.

Thanks.

 

[loganj]

The RO/DI water is completely demineralized. When you mix SW mix with it, you're adding the needed minerals back in which is why it's so great for SW tanks. Perfectly clean water with just the right stuff added back to it. For FW tanks, you'd need to use something like RO Right or some other product that will add some mineral content back into the water. RO/DI water is neutral pH (7.0) but it has no buffering capacity at all. The slightest addition of a base or acid will cause large swings in the pH...hence the need to remineralize it. If you aren't having any problems with your FW tanks as far as water quality goes, I would probably stick with tap water.

 

[steve5520]

Thanks. I guess that makes perfect sense. Why filter it out and then have to add stuff right back in?

I appreciate the help.

 

[loganj]

As long as you don't have water quality issues with the tap water. I just read an article in FAMA where a guy was losing fish like crazy. Turns out his water had a high level of zinc due to a galvanized well casing and galvanized plumbing...makes me wonder...the plumbing in this old house is galvanized and copper. But if your tap water is OK, I'd continue to use it as is.

 

[AJ]

If you use only RO/DI water you have to add sodium bicarbonate (baking soda) to the water to prevent pH flux, this will kill the fish.

 

[shawmutt]

Turns out his water had a high level of zinc due to a galvanized well casing and galvanized plumbing...makes me wonder...the plumbing in this old house is galvanized and copper.

That may be what was killing my fish! The galvanized pipes are so old in this building that we barely have any water pressure.

I use ro water in my tanks, I buy it from the store. In my amazon tank I add electro-right (which will also work in a community 7.0 tank), and in my african tank I use a mixture of sea salt, epsom salt, and baking soda to bring the water up to acceptable pH and hardness levels. I got the recipe here: http://www.cichlid-forum.com/articles/buffer_recipe.php.

 

[justDIY]

old galvanised pipes won't be leaching zinc, especially if they're clogged... most likely they will have lost their zinc coating a long time back and have built up a nice thick coating of a mixture of calcium salts (maybe magnesium as well) and of course rust...

the fact that all that is building up in the pipes means the water cannot hold onto it due to the water being already super-saturated with it and is depositing it whenever possible. however, if the water in the pipes sits "off" for too long, some of that may dissolve or become suspended in the water... in that case, allowing your water to run for 10-20 seconds before using it would likely bypass most of the junk!

as for the copper leaching, that is possible - maybe investing in a copper test kit would determine what's going on there.