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Do I need a reverse osmosis machine for rain water and hydroponics?

Douglas.Curtis

Autistic Diplomat in Training
Depends on what's in your rain water. *Most* places away from industry are ok, better to check your area specifically.

Personally I go with r/o and forget about it. I can give and get advice from any other r/o hydro guy and it applies directly to my garden. Doesn't rain much in the places I've lived the last 15 years. :)
 

OldPhart

Member
Is there cheaper or longer lasting filters that would do the job?

The RO system I just got a few months ago was about $120, with tank and faucet; because I also use it for drinking water. I plan on replacing the pre-filters every 6 months, and the membrane every 2 years. I expect to spend about $80 on 4 sets of pre-filters, and a new membrane. So I'm only looking at about $40 per year to maintain the filter. By my standards, that is pretty cheep and long lasting for what I get out of it; which is not even having to think about water quality. What can I say, I'm a lazy bastard.
 

t33to

Member
The RO system I just got a few months ago was about $120, with tank and faucet; because I also use it for drinking water. I plan on replacing the pre-filters every 6 months, and the membrane every 2 years. I expect to spend about $80 on 4 sets of pre-filters, and a new membrane. So I'm only looking at about $40 per year to maintain the filter. By my standards, that is pretty cheep and long lasting for what I get out of it; which is not even having to think about water quality. What can I say, I'm a lazy bastard.

Can you link me to the parts you are using.

The only reason I ask is because it seems like a lot of RO systems I see for sale talk about removing chlorine from tap water. My issue is that all of my hydroponic experiments so far using rainwater always sooner or later end up with the plant dying very rapidly (48hrs). They look as though they are dying from not getting enough water which is absurd in a hydroponic environment. So I started thinking it's probably some kind of root slime that's suffocating the roots, which lead me to believe it's from organic particles or organisms that live in my cistern. So if I just need to remove organics from my water, do I need an RO system for that.

At any rate, please link me to the parts you are using as that sounds like what I want to spend and I like how rare you'll be changing filters.
 

OldPhart

Member
If all you are trying to do is remove organics, an RO system is NOT what you need. I would think you need something like a UV sterilization system, with a good particulate filter before it.

yes, any RO system MUST remove the chlorine from the water before passing it through the membrane; because the chlorine will damage the membrane. Removing chlorine and VOCs is the purpose of the prefilters; but the membrane is where the magic happens, it actually removes about 90% of dissolved substances in the water.

This is the RO system that I got, but you need to supply this filter with "safe" (no living microbes) drinking water. So no untreated water should be ran into it. https://www.amazon.com/AquaLutio-Premium-Filtration-Drinking-Designer/dp/B01HFH2UHG I plan on just getting generic filters off Ebay when it needs them. You can normally get a set of pre filters off Ebay for about $15, and a full set including membrane and post filter for about $30. This is in the US, so I'm not sure how accurate these numbers may be for where you're at.
 

troutman

Seed Whore
Normally rain will be good to go as is.

It's not like it should have a lot of dissolved solids in it.

It may have a slightly acidic pH other than that I say use it.
 

Spaventa

...
Veteran
I have a 1 sq. Meter or 3'x3' , flowering space based on a Nutriculture Amazon Aeroponic system (50 litre res) and a single 600w light. A 10 week run uses 200 to 250 litres of water. I buy it from Aldi for like £20. Nutes and electric on that run is £190 so...
 
Sounds strange, try this. Fill a clean water bottle and set it next to your plants. Does it grow bacteria? Yes, then filter or pre charge with beneficials to eat the bad stuff. If there is allot of particles that you can see as a bacterial growth or other contamination then filtering is a really good idea. But you might be able to use a conventional two part filter, because ro is great to clean heavy metals, salt (mostly), and everything else. But they produce lots of waste water and the cost of materials is high. I had one and didn't like it, so much waste.
Typically the rain will be similar to ro, not much can collect on the h2o molecules in upper atmosphere depending on where you live. Kind of a natural distillation process.
Rain is typically very low in EC, what you might be seeing is either underfeeding from the lack of macronutrients, or your ec isn't high enough for the plants liking. Do you use a measuring tool? You can see what the EC is starting out.
If the plant is wilting there could be a few reasons for that, including a bacterial growth. But you should be able to see the stuff floating in the res. What I've done for that in the past is to use maybe a drop or two of bleach per gallon then let sit overnight before using.
Take pics if you want a real eye view opinion
 

Douglas.Curtis

Autistic Diplomat in Training
ro is great to clean heavy metals, salt (mostly), and everything else. But they produce lots of waste water and the cost of materials is high. I had one and didn't like it, so much waste.
There is zero waste from an r/o machine, until you throw away the "waste" water. R/O machines also work quite well with 1:1 restrictions, allowing a single gallon of garden/lawn/flowers/car-wash water for each gallon of r/o you produce. :tiphat:
 

t33to

Member
Sounds strange, try this. Fill a clean water bottle and set it next to your plants. Does it grow bacteria? Yes, then filter or pre charge with beneficials to eat the bad stuff. If there is allot of particles that you can see as a bacterial growth or other contamination then filtering is a really good idea. But you might be able to use a conventional two part filter, because ro is great to clean heavy metals, salt (mostly), and everything else. But they produce lots of waste water and the cost of materials is high. I had one and didn't like it, so much waste.
Typically the rain will be similar to ro, not much can collect on the h2o molecules in upper atmosphere depending on where you live. Kind of a natural distillation process.
Rain is typically very low in EC, what you might be seeing is either underfeeding from the lack of macronutrients, or your ec isn't high enough for the plants liking. Do you use a measuring tool? You can see what the EC is starting out.
If the plant is wilting there could be a few reasons for that, including a bacterial growth. But you should be able to see the stuff floating in the res. What I've done for that in the past is to use maybe a drop or two of bleach per gallon then let sit overnight before using.
Take pics if you want a real eye view opinion

Well it's rain water, so it falls through the air, picks up any kind of algal spore and particulate on it's way down, then touches my roof, which has bird shit, pine needles, leaf matter, dead bugs etc, then goes into my gutters which I do my best to keep clean, but are also littered with other parts of nature, and then fall into my cistern, which I can easily see has the odd pine needle and other organic matter in it. The water itself has a slight yellow tinge to it.

I don't have a hydro experiment currently underway so I can't take photos for you. I have a bluelab meter, I check salinity with PPM (it can do EC though) and it registers as 30ppm right out of the cistern.

During my experiments I was adding 1ppm of bleach to my rez. It worked well for a little bit but then the plants died rapidly. This has happened 3 times in a row but at various lengths of growth. I think the longest my hydro plants survived was 6 weeks.

Normally I buy drinking water from the Grocery store, but I thought I'll get an RO system and then I can drink my cistern water and switch to Hydro.

Sounds like I might need an RO machine and UV machine.
 

OldPhart

Member
If that is the only water you have to work with, I think I would pursue chemically treating the water in some kind of storage tank. Then work on filtering out the particulate matter and the chlorine (or what ever oxidizer you choose) after it is 'safe' to drink. 30 ppm isn't much, it would be nice to know what makes up that 30ppm, but it shouldn't cause too much havoc, so I don't know that I would pursue RO. I'm thinking hauling water may be a better option than trying to turn that water into potable water; which in my opinion is what you need to do. If I wouldn't be willing to drink it, I don't think I would want to put it into a hydro system. Bottom line, I think this is a bit more of a task than popping a filter on, or dumping a little bleach in; and not sure it is worth it. But that is something that you would need to decide.
 

t33to

Member
If that is the only water you have to work with, I think I would pursue chemically treating the water in some kind of storage tank. Then work on filtering out the particulate matter and the chlorine (or what ever oxidizer you choose) after it is 'safe' to drink. 30 ppm isn't much, it would be nice to know what makes up that 30ppm, but it shouldn't cause too much havoc, so I don't know that I would pursue RO. I'm thinking hauling water may be a better option than trying to turn that water into potable water; which in my opinion is what you need to do. If I wouldn't be willing to drink it, I don't think I would want to put it into a hydro system. Bottom line, I think this is a bit more of a task than popping a filter on, or dumping a little bleach in; and not sure it is worth it. But that is something that you would need to decide.

That's good honest advice. I appreciate it. Thank you.
 
I've used well water, seasonal​ creek water, river water, City water, city water on ro, well water on ro, and currently rain water stored in a very large plastic tank.

I honestly don't believe it's your water that is the problem. If you fill a bottle of water and let it sit in your grow room, you will see what is growing in it. You can even add a drop of molasses to feed the bacteria and funji, that will speed up the process.
 

delta9nxs

No Jive Productions
Veteran
hey buddy! 30 ppm is nothing! i let my ro filters get dirtier than that before changing. even if it is organic contaminant of some kind there is just not enough of it to kill your plants unless there is a toxin of some kind involved.

by your description of a delayed response it could possibly be an algal bloom that uses up all the free o2 and then dies, releasing toxins. but you would be seeing algae in the water.

i didn't see a mention of ph? algal blooms can cause rapid ph changes.

"The water itself has a slight yellow tinge to it." typically plant matter decaying in water gives off tannin and has a yellow/orange tint to it.

what is your cistern ph?

what nutrients are you using?
 

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