Watering with rainwater: some questions

[orchids44]

I purchased a food grade 55 gallon rain barrel for $50 from Craigslist about a year ago. My orchids and wallet couldn't be happier. Our municipal water in central North Carolina is too harsh, the pH is about 8.0 - 8.5. Since changing over to rain water the orchids are perkier, less pests/diseases and bloom more frequently. I wonder if they absorb the necessary nutrients better without the salt residue on their roots. I feel as though I can control what's fed to them because the basic water is pure and not a lot of guessing of what's in tap water. Just my from observations of my chids.

[catherinecarney]

I've decided I never will understand people, RandomGemini.....

At least they're using greywater recycling, so that's a start...

Subrosa, I have even harder water (300+ppm out of the well, lots of calcium, magnesium, and iron) which we affectionately refer to as "liquid rock." Rift lake cichlids and central american species love it, pretty much everything else struggles unless I dilute it 50/50 with rainwater, but even with that I don't think I'd try tetras. The waste water from the tanks is softer since the tannins and organics seem to bind the ions or cause them to precipitate (not sure which), so the orchids (and the rest of the plants) seem to thrive on it....

[Polarizeme]

Originally Posted by Subrosa

My rainwater collection system consist of an approx 300 gal container with a 5 gal bucket sitting on top full of pond filter pads. There's also a valve between the bucket and the collection container which allows me to bypass the collection container and feed into the normal runoff system. This is nice when we haven't had rain for a while as it allows the rain to rinse crud off the roof and gutters before I divert the water into the collection container. I still get little bits of leaf material in the water, but I'm not worried about it. My Lemon Tetras live in the same water and breed like flies.

This is the same system we use for our rainwater catch system. The bucket can be taken off in the summer and cleaned out.

[Dusty Ol' Man]

I've decided to resurrect this old thread because I'm sure there are those of us here now have things to add that could be of benefit. I collect roof runoff to a rain barrel (commercial) and use it exclusively on my orchids. Our local tap has so much chlorine in it that you can smell it. Lately we have seen very little rain, which is unusual for this area in spring. The water coming out of the barrel is taking on a decidedly brown hue. The barrel is opaque and has screens over the incoming downspout and overflow. I've seen algae at the overflow. Is the discoloration something to investigate further? It hasn't harmed the plants so far. Opinions please.

[estación seca]

I collect rain. I have a flat foam roof inclined about 15 degrees. I put Rubbermaid brand livestock tanks at the drainage points. I use a sump pump and garden hose to pump the water into large black plastic lidded trash barrels.

Chlorine will evaporate if you draw water and let it stand overnight. During some parts of the summer ours is very chlorinated but I haven't noticed any problems using it on plants.

Serratia are water bacteria having a reddish or brown hue. There are brown algae that prefer warm to hot temperatures. I've never had problem using the water on my plants when I have brown biofilm on the insides of containers.

Based on a lecture I heard, it would probably be better to have translucent or clear water storage and let the algae grow. The algae outcompete pathogens and provide a substantial amount of nutrients to plants watered with the green water. There are farmers in western Arizona fertilizing with nothing but green water that has stood in large translucent tanks for many days.

[Diane56Victor]

Wow some of your state governments really give you a hard time regarding water collection.
Here its encouraged, new homes in South Australia have mandatory plumbing installed for a 1000 litre (264 US gallons, 220 UK gallons) tank to be used for flushing the toilet, it's system that can only be used for that purpose. I know, its a bit of a drop in the ocean but its a start. Sorry about the pun!
In some states local councils even give a little financial help every now and again towards other tank purchases.
Last house we had 14000 litres (3699 US gallons or 3080 UK gallons) of storage over 3 tanks fed from the house and a large outbuilding for watering the garden. Being suburban Adelaide we were subject to weeks of extreme high temperatures and despite robust plants the garden needed the extra collected water.
This house with a lot smaller garden we have one 5000 litre tank (1321 US gallons, 1100 UK gallons). It's fed from the house and verandah roof. The tank has a filter at the entry. Its mainly used for my orchids as we get more temperate weather with better rainfall so the garden, planted with plants suited to area grows well on natural rainfall.
I have ph and tds tested the tank water and everything is in acceptable range.
I don't worry about anything on the roof as others have said it wouldn't be much, plus we live in a small country town by the sea so the dirt washoff is minimal.

[Dimples]

Water allocation methods in the western part of the US is the main reason why some states have made rain collection illegal. The water in the surface systems (creeks, rivers, etc.) has already been allocated to various uses/users by percentage of a set expected annual total gallons in most states. The fear is that if people start collecting rain water in mass, then the municipalities won’t be able to meet their existing water obligations. There’s a push to change the allocation system to be more reflective of today’s water reality, but not all stakeholders want to renegotiate the terms so we’re stuck for now.

We need to be less concerned about people collecting rain water and more concerned with addressing the real cause of water shortages in the west, climate change and highly inappropriate landscape choices.

[estación seca]

The great majority of water in California is allowed to run to the sea or used for agriculture, not city water systems.
Water Use in California - Public Policy Institute of California

Statewide, average water use is roughly 50% environmental, 40% agricultural, and 10% urban, although the percentage of water use by sector varies dramatically across regions and between wet and dry years.

While collecting rain and greywater (soapy runoff from kitchens, showers, laundry and bath tubs) is illegal in most of metro Phoenix, the various water agencies have said they want people to collect and use this water. They look the other way. I collect almost all the water from my kitchen sink. I use large plastic basins for washing, then empty them into a 5 gallon bucket I take outside to put on various landscape plants.

[Dusty Ol' Man]

Please people. Let's not take this conversation there. It will raise some ugly monsters. Let's stay on topic. The politics of water management has no place here.

[isurus79]

Originally Posted by Dusty Ol' Man

The barrel is opaque and has screens over the incoming downspout and overflow. I've seen algae at the overflow. Is the discoloration something to investigate further? It hasn't harmed the plants so far. Opinions please.

We have 40,000 gallon catchment for our house and a 2,500 gallon catchment for my plants. The pollen and catkins falling off the oaks always stains the water this time of year here in central Texas, so my guess would be something similar for Louisiana. Consider it as free plant fertilizer!