Newbie trying to figure out water options: well water (tested) and/or purchased RO water

[clownfish:)]

Hello! I've recently purchased my third tank, a 30 gallon, and I'd love to set it up as saltwater. (My other two are freshwater.) I've been digging through the research, but I'd really appreciate some outside perspective and advice. My biggest hurdle, right now, is deciding on water.

I've seen that RO/DI systems are strongly recommended, but I'd really rather avoid purchasing one, as A) It isn't really where I'm wanting to spend my money, B) we have very poor water pressure, and C) I am a teen, and I don't think my parents want to help install plumbing equipment.

I realize that well water can offer complications to reef tanks, due to the many unknowns, but ours has been tested in a lab for safety, so I found the results (~2 years old, and we can only get it tested every 3 years, unfortunately.)

Some more notable, potentially risky results of our well water testing are:
(NOTE: this is PRE-FILTER, and we have a carbon filter, sediment filter, and fluoride removal filter.)

pH of 8.7
copper at 0.003 ppm / 3 ppb
iron at 0.10 ppm
nitrite at 0.51 ppm
TDS at 779 ppm (with test strips, after the filter, our gH is extremely low)
alkalinity at 445 ppm / 25.4 dKh

Unfortunately, ammonia, phosphates, and silicates were not included in the test, though I'm hoping to pick up a few tests next time I visit my LPS (which is, unfortunately, an hour away.)

Nitrates were not found, nor any lead, or mercury. Dangerous bacteria also came back negative. Our water is not chlorinated, though it does contain chloride ions at approximately 5.1 ppm.
Calcium (2.9 ppm) and Magnesium (0.48 ppm) are both very low. The lack of Calcium is somewhat confusing, considering the incredibly high alkalinity, but I believe the alkalinity is a result of sodium carbonates/sodium bicarbonates as opposed to calcium carbonate, evidenced by the higher sodium content of 313 ppm.

I am supplementing with RO water in 5 gallon jugs, and hoping to set up a rain barrel once spring/summer comes (Canadian winters take forever...)

So my question is—could my well water be used? With cuprisorb, or other added removal? Obviously I'd have to dose Magnesium and Calcium. Should I try to mix it with RO? Avoid using it entirely?

Sorry for the massive post, any questions/advice/comments/concerns are deeply appreciated!!!!

 

[Jason_MrFrags]

Using well water without RODI would be a recipe for disaster. You would end up with a tank full of algae

 

[Stephen8169301]

@clownfish:) Just saw your lfs thing lol maybe try and do a distilled boiling water process?

 

[CoastalTownLayabout]

If you’ve got a reasonably clean collection surface don’t be afraid of using rain water, especially if you’re not in a heavily urbanised area. It stores well so you can stock up reasonable volumes if you get your set up right.

I switched to it from RO DI around 5 years ago and haven’t had any problems. I use it for ATO top up only, because I’ve got good access to clean natural seawater for water changes. Can’t comment on its effectiveness with commercially available salt mixes.

 

[arbiter42]

@clownfish:) what did you end up doing here? I'm setting up a 200-ish gallon system in a similar situation and trying to figure out what to do.

 

[Gumbies R Us]

Curious to know what you decided to go with!