What I found is that your area is over a lot of limestone. Frankfort reports a TDS of 190ppm, Lexington reports 215ppm, and Louisville states 105ppm. You could probably take 2-1/2 gallons of your tap water (Frankfort) and add it to a gallon of distilled 0ppm water and come up with water a tad over 50ppm. But, there's still the issue of chlorine and chloramines being present.
Rainwater is actually better at giving carnivorous plants the conditions they need. Tap water is usually neutral to alkaline. Rainwater is mostly acidic. Rainwater is also very low in minerals, sometimes as low as 0ppm. Mine usually runs less than 5ppm and lots of the time 0-2ppm. The lower ppm readings come with long rains that have a chance to rinse the roof off and also has a chance to clean the atmosphere.
Yes cisterns and water tanks have been around for centuries to catch rainwater. Both for drinking, household use, and for watering plants. I'm like Panman, I wouldn't be drinking it.
It is truly amazing how much water you can get using a roof. I don't have a gutter system but I can only imagine the efficiency that they create in catching rainwater. Take one of your buckets and multiply the area of it's surface by a couple of thousand times and you can see the difference between the amount of free-falling rain you can catch and how much you can catch using a roof system. Mega-magnitudes of difference.
All the crap that has landed on your apartment's roof through the years just doesn't sit there...it eventually gets washed away with the rains. It is common for the first several minutes of rain that comes off a roof to be dirty. That is why it is recommended to toss that first water. There is definitely a difference in quality of early runoff and later runoff. For people who have rain barrels set up there are valves that actually divert the first rain that falls to waste...then the valve closes and allows the cleaner water to go to the barrels.
I filter my rainwater through a thin cotton cloth beneath a coarser towel. It takes a little time but it goes fast enough for me...for now.
Lots of people don't worry about filtering. To be honest, sometimes I use fresh rainwater that hasn't been filtered...the water I usually filter is rainwater that I intend to store. I don't sterilize, boil, nuke, or do anything else to it.
The water coming off your roof and down through your gutters may be nasty as can be or it may be just fine. I think I mentioned a TDS meter earlier, it can give you a clue about the water's quality. Naturally it can't tell you everything, but if the TDS measures below 50ppm I probably wouldn't dig much deeper.
Your buckets sitting beneath the wide open sky will catch some rain, but you need a heavy rain that lasts for a while to even think about filling them up. A two inch rain will yield roughly 0.7 gallons in a 10" diameter bucket. The water should be pretty clean, though. For a few plants, the group of buckets should collect a fair amount of water that will last for a while. Always figure on having a "Plan B" in the case of no rain, little rain, etc.,. Your Zero pitcher can be "Plan B".
People use TDS of different ranges. I've always held to "below 50ppm" in my short spell in the CP hobby. This seems to be the recommended level. Many people use a bit higher ppm but also flush their pots either naturally via rain or by using distilled or very low TDS rainwater and top watering. Top watering also brings oxygen down into the grow mix.
Be aware that the Zero pitcher's filter can fill up quickly with high-mineral, dirty water. For a few plants they should work well. But, for a few plants...say three or four pots that will be indoors (not in the summer heat) a gallon of distilled water should last for a decent amount of time...and is cheap and easy, too.
I wouldn't add anything to the water. Low/no-nutrient water and grow mix is what they need. They'll they their food using the sun and get their fertilizer from bugs they catch (or food you feed them).
Using the tarp to collect your rain will increase your yield dramatically. It might take some trial and error, but it'll work. I still wouldn't rule out the apartment roof drainage yet, though. At least not until you check the water with a TDS meter. Let it rain for several minutes to rinse the roof before testing the runoff water.
Remember when selecting plants that most of them have high intensity light requirements. Windowsills mostly only work well for some sundews. Flytraps and pitchers will require more light than a windowsill. Just sayin'...
Fenlena wrote: ↑Wed Jun 07, 2023 6:42 pm
From what I have gathered, there is nothing wrong with watering your plants with rainwater from your gutters as long as you filter out debris and dissolved solids and sterilize it. People have contraptions set up that funnel gutter water directly into huge reservoirs. It seems to be a nice arrangement that doesn't involve much effort and apparently results in huge amounts of water.
I can't help but think about all the crap that has landed on the roof of my apartment over the years. For all I know, there could be dead squirrels in the gutters. I'm certainly not going up there to find out. But even in the best case scenario, the rain coming out of my gutters has most likely traveled some distance on the roof, mixing with tar and dirt and bird poop, before being deposited into the rusty metal gutters that funnel all the water down to an easy collection source.
These buckets are sitting under wide open sky. No power lines above, no shade trees or buildings or gutters. Which means that the rain falling into them is pretty much as pure as I could hope for. It's at least a zillion times cleaner than the water coming out of my tap. I checked the local tap water quality for Frankfort, Ky at the utility company website. I'm seriously considering bathing in rain water. I digress.
Would you drink this water after it has been boiled and passed through a ZeroWater pitcher filter? If not, what else would you do to it before you felt safe to drink it? I do plan on cleaning the buckets with bleach before I use them to collect drinking water but I think the regular house plants I have now will be fine with what I catch today. We are paying maybe $7.00? for 5 gallons of drinking water currently. Not bad, but it adds up with 5 people, a cat, and several house plants drinking water all day long.
What else would you do to this water before watering your carnivorous plants with it? My TDS meter will arrive with my ZeroWater pitcher. I believe I am aiming for somewhere south of 70 ppm, except for nepenthes, which can handle up to 150ppm? I'd imagine I probably want to boil it before giving it to the plants but from what I gathered, I don't need to run it through the ZeroWater pitcher unless the ppm is higher than 70ppm? What if it is naturally below 50ppm and I want to grow nepenthes? What should I add to the water to give the plants what they need?
I do plan on setting up a tarp collection system that can be easily folded away when not in use. I live in an apartment so I can't leave stuff like that out. It probably won't be much to look at but I will post pics and discuss any snags I ran into along the way.