Rain water instead of rodi

[sixty_reefer]

Hi folks, I’m looking at starting a new build soon and was looking at some natural and simple approach to the hobby, one of the aspects I have been pondering was to collect rain water (not short of it as I live in the uk) instead of using RoDI. Any thoughts on it? Is there any disadvantages that I may be overlooking some earlier test showed to be zero tds in my area.

 

[ISpeakForTheSeas]

There could potentially be issues with the rain water depending on weather, season, location, etc.; so, it wouldn't be as consistent or reliable as RO/DI, but it could work depending on what the rain comes in contact with before ending up in your collection container:

It depends on the rainwater, but - given how sensitive inverts are to copper - I wouldn't assume so. To quote the top link below, "copper was above the ADWG (2.0 ppm) in eight samples out of 365 samples," (ADWG meaning Australian Drinking Water Guidelines) - 2.0 ppm may not seem like much, but it is substantially higher than the ~0.002 to 0.2 ppm LC50 of Copper.

Lead, Zinc, Copper, and Cadmium Content of Water from South Australian Rainwater Tanks - PMC

Rainwater is consumed for drinking water in many parts of Australia, either preferentially over municipal water or in regional or remote areas, because rainwater is the primary source of water. Previous rainwater studies in other areas in Australia ...

www.ncbi.nlm.nih.gov

https://apps.ecology.wa.gov/publications/documents/1903008.pdf

 

[PharmrJohn]

There could potentially be issues with the rain water depending on weather, season, location, etc.; so, it wouldn't be as consistent or reliable as RO/DI, but it could work depending on what the rain comes in contact with before ending up in your collection container:

There can be a lot of particulates in rain water depending on weather conditions, pollen count, etc, etc. RODI is the way to go.

 

[AetherealKnight]

 

[GARRIGA]

Thinking the same thing. Just run the rain water through sediment, carbon block and DI. Google rain water capture. There’s filtration systems dedicated to this process. Biggest concern on how it’s captured. I’m considering installing gutters that won’t leach metals. Something I need to install regardless therefore might as well take it a step further and capture the run off vs plumbing it to the street.

 

[kyreefville]

Some people just use natural seawater, I watched a well known hobbyist in Colorado use unfiltered tap water and mentioned beneficial minerals in the water. All such choices have potential risks. Most will only consider rodi due to potential build up of toxins associated with water top offs. I’ve not seen anyone mention building a solar still.

 

[CoastalTownLayabout]

I’ve used collected rainwater as top off for over a decade with no issues observed keeping softies, LPS or easy SPS. I don’t filter it at all and when I tested it many years ago it had very low to undetectable nutrients and a slightly lower ph than RODI.

I probably wouldn’t use it if I lived in a major city or if I kept high end corals. For a natural system with easier corals I see no real problems.

 

[kyreefville]

I’m no chemist is the lower ph due to lack of disolved calcium? Is low ph also typical for distilled water?

 

[polyppal]

I wouldnt, Rain water isnt refined/clean water in the same way distilled is

 

[Australian_Reef]

I lived away from town water for several years and we only had rainwater. I like it to drink but I wouldn’t use it in my reef. You may get away with it for a while but you will be adding extra stuff in that can build up over time, especially in the UK where unless you live in the Scottish west coast you are never far from sources of pollution. It’s just not worth the risk when an RODI unit is going to be such a small fraction of the overall cost of a reef system.
Perfectly fine to run that rain water through an RODI unit with a booster pump though and use the actual water that way. I know people that do this regularly.

 

[PharmrJohn]

That's sadly reminiscent of the 70s. We had acid rain back then.

 

[CoastalTownLayabout]

Yes, you should probably spend as much money as possible on the most aggressive filtration hardware the hobby has to offer. Then spend more money on the best additives to raise your nutrients because you’re terrified of dinoflagellates.

Seriously though, pure rainwater is as clean as you need for a reef tank. Pollutants are additional and will vary from location to location depending on air quality and your collection surface area.

Just test it and make an informed decision.

 

[PharmrJohn]

Yes, you should probably spend as much money as possible on the most aggressive filtration hardware the hobby has to offer. Then spend more money on the best additives to raise your nutrients because you’re terrified of dinoflagellates.

Seriously though, pure rainwater is as clean as you need for a reef tank. Pollutants are additional and will vary from location to location depending on air quality and your collection surface area.

Just test it and make an informed decision.

I used to live in a place where we'd use rainwater run off (the roof) into a 1000g barrel to use for showering and dishes. It was great in the fall, winter and spring. Not so much in the summer.....

 

[sixty_reefer]

There could potentially be issues with the rain water depending on weather, season, location, etc.; so, it wouldn't be as consistent or reliable as RO/DI, but it could work depending on what the rain comes in contact with before ending up in your collection container:

We do get very clean ish rain water over here. All our drinking water comes from reservoirs that collect rainwater and then chemically treated.

 

[sixty_reefer]

Thinking the same thing. Just run the rain water through sediment, carbon block and DI. Google rain water capture. There’s filtration systems dedicated to this process. Biggest concern on how it’s captured. I’m considering installing gutters that won’t leach metals. Something I need to install regardless therefore might as well take it a step further and capture the run off vs plumbing it to the street.

I have a new roof and plastic guttering at the moment might send a sample for icp just to be sure on what’s in it

 

[Solo McReefer]

I have a new roof and plastic guttering at the moment might send a sample for icp just to be sure on what’s in it

Send an AquaBiomics sample in as well

 

[sixty_reefer]

Some people just use natural seawater, I watched a well known hobbyist in Colorado use unfiltered tap water and mentioned beneficial minerals in the water. All such choices have potential risks. Most will only consider rodi due to potential build up of toxins associated with water top offs. I’ve not seen anyone mention building a solar still.

Hi, NSW would be the closest from natural as it can get, I’ve looked at that possibility also but it meant 3 hours round trip every time I needed water. I did seen a reef of the month running with tap water as a top up

 

[sixty_reefer]

I’ve used collected rainwater as top off for over a decade with no issues observed keeping softies, LPS or easy SPS. I don’t filter it at all and when I tested it many years ago it had very low to undetectable nutrients and a slightly lower ph than RODI.

I probably wouldn’t use it if I lived in a major city or if I kept high end corals. For a natural system with easier corals I see no real problems.

Thank you, that’s some of the insight information I was looking for. I’m not planning on keeping any high end corals. It will be a NPS system with very dim light.
Did you aerate the collected water or just kept it in a water but until needed.

 

[GARRIGA]

I have a new roof and plastic guttering at the moment might send a sample for icp just to be sure on what’s in it

Perfect. Can’t imagine any contaminants can’t be removed by items I’ve mentioned. Basically remove the RO from an RODI and stop throwing water away just to make water.

 

[GARRIGA]

BTW, based on roof material used, might be cheaper longterm best use an RODI yet still not wasting water to make water and might be less of an issue to plumb. My current issue and why moving everything outdoors likely works for me. Using DI alone might get costly for some.

Due to water height. Might be enough pressure to utilize an RO membrane but not sure on that. Could have a bypass to allow excess water or just invest in a larger unit. Where I live rain sone says can fill a five gallon quickly.