Hey soil growers: For those using RO water, if you add cal-mag, what do you like to get your ppm to? I don't normally use RO water, but the tap is very hard, so going with it this time. I have a reservoir in an SIP set up, so it's difficult to measure ml/gal, so would rather rely on ppm to dial in the cal-mag. Cheers, and have a nice weekend. Thanks for reading / replying.
Soil growers don't usually test ppm. Just feed the cal/mag according to the directions on the supplement or as low as 50% what they recommend to start. PPM meters and checking that kind of thing is more of what a hydro grower does. That's the benefit of soil is not having to pay attention to that. RO water is usually 0ppm. How high your cal/mag supp raises it is a little irrelevant. Your SIP setup makes no difference. Just top it off with measured amounts. Use a 1 gallon or 1/2 gallon garden pour spout to fill the sip but add your cal/mag to that gallon so you can balance it out.
The RO water is always 0 ppm, yes, obviously until the cal-mag is addee. You didn't really answer the question, Tbone. Ppm is still important (not as important as for Hydro, arguably)
Follow the dosage level for the directions on the supplement. Start at 50% strength. If you do that it really doesn't matter where the ppm is. I could make a batch and just put some cal/mag in it for you but my guess is that the ppm would be about 50-100 with just cal/mag in there.
The whole point of this thread was specifically about not using the milliliter to gallon directions. The whole point was about PPM. I guess I will just mix up a batch per the instructions and measure PPM.
I think I finally understand what you're asking. You want to test the water in the bottom of your SIP to see if you still have enough cal/mag in there. I still think don't think you want to rely on those numbers. Just because it's an SIP system doesn't mean that the plant doesn't have a normal feed rate. If the feed water that you originally put in there was good for a cal/mag dose it should last until the plant needs more feeding. I don't add more cal/mag only to my DWC hydro res as it depletes when the plant feeds. I top it off with more feed water that has been dosed the same ml/gallon ratio I always feed it. Continually adding just cal/mag to a res to keep a certain ppm is fine for a while but eventually it's a recipe for toxicity. Cal/mag supps also have iron in them among other elements. The plant only uptakes what it can use and leaves the rest behind. Iron only makes up .01% of the feed though so even at toxic levels it won't effect your ppm. In true hydro the res is changed every week to 10 days to combat accumulation of things. You could add a drain to your setup and commit to a water change once a week. Then you could add an airstone and treat it like a hydro res. I actually have been thinking of trying this. I think with a standard SIP setup and soil you'd be better off watching the plant for signs of cal/mag deficiency and feeding it a prescribed amount then treating it like a DWC plant and testing the ppm in the res. The problem with balancing the ppm in your sip res is you don't change the water or use an airstone. It's not a hydro res you can't treat it and test it like it is. If you're using soil you can forget even using a cal/mag supplement and next time mix 2tablespoons per gallon of dolomite lime per gallon of pot size. Halfway through the grow make some balls of it and push them down in the soil to make sure it's not depleted in flower. If your soil was of a decent build in the first place it should have plenty of the stuff. It's what organic growers use for calmag so they can just feed water. It's also a ph buffer so your feed water can be off a little.
Use tap water. RO water and other filtered waters are stripped of micronutrients they need and use. I've seen people get weird deficiencies from using it. Make sure you pH your water and never water till you can lift the container and feel NO weight. Keep defined wet/dry cycles always for healthy plants. Good luck. TWW
I don't believe in the whole wet/ dry cycle. Hence the use of a SIP setup. The tap is very hard - over 420 (ha) ppm, mineral deposits on faucets, etc. Thanks though.
I'm in soil and my tap water is 18 ppm. I add Cal/Mag until tds meter reads between 100-150 ppm. Sent from my iPhone using Grasscity Forum
Awesome. That's the kind of answer I was looking for. That's really low ppm for tap water, by the way.
How does an aquaponic system work then? Aeroponic? DWC? Self Irrigating Planters? Organic soil that is kept constantly moist? Wet/dry cycles are a load of crap. IMO - of course. J
When I mix ca/mg to RO it adds about 400 ppm on the 700 scale. Sent from my iPhone using Grasscity Forum
I feel like an idiot. What's the 700 scale? My reader is putting me at around 250 ppm after the cal-mag is added. My biggest concern, honestly, was overdoing it and having a lockout.
Don't know if I'm supposed to quote other sites, but this is from GYO; What's the difference? The ppm 700 scale is based on measuring the KCl or potassium chloride content of a solution. The ppm 500 is based on measuring the NaCl or sodium chloride content of a solution and is also referred to as TDS - total dissolved solids. Individual nutrient ions have different electrical effects! The true ppm of a solution can only be determined by a chemical analysis. ppm cannot be accurately measured by a CF or EC meter. They are present on Bluelab products as a conversion guide only. The conversion is as follows: 2.4EC x 500 = 1200ppm (500 scale) or 1200ppm / 500 = 2.4EC 2.4EC x 700 = 1680ppm (700 scale) or 1680ppm / 700 = 2.4EC If you are reading from a book that says you should grow your crop at 1100ppm - how do you know which scale the writer is referring to? Is the scale on your ppm meter right for the job? If the book was written in the USA, it could be the 650 or 500 scale. If the book is written in the UK, it could be the 700 scale. If it was written in Australia, well it could be any of the three! If you must grow using ppm, you will need to know the following; What ppm scale is the book referring to? What ppm scale is your meter using? Which standard or calibration solution should you use for your meter? What ppm scale is the nutrient formula referring to? (Courtesy of BlueLab) ------------------------------------------------------------------------------------- At GYOstuff, we do the research so you don't have to. So let's get to it... What PPM scale is your nutrient formula referring to? Manufacturer Scale Advanced Nutrients 700 scale Botanicare 700 scale CES/Cutting Edge Solutions 500 scale Dutch Master 500 scale Dyna-Gro 500 scale FoxFarm 700 scale using dechlorinated tap water General Hydroponics 500 scale using reverse osmosis water General Organics 500 scale using reverse osmosis water House & Garden 700 scale Humboldt Nutrients 500 scale Hydro Organics/Earth Juice 500 scale Nectar for the Gods 700 scale Rock Nutrients 700 scale Roots Organics 500 scale Rx Green Solutions 500 scale using distilled water Soul 500 scale Technaflora 500 scale Sent from my iPhone using Grasscity Forum
Now that I think about it. It was irresponsible of me to just cut and paste the first thing I found. Someone else could probably give a better explanation than what I found. Please disregard. Sent from my iPhone using Grasscity Forum
Tao water consists of chlorine fluoride chloramine ammonia all shit that plants do not want need or ask for man. That's just plain bad advice. Lol. Don't airate ro mate it will constantly change ph You'll find it pretty hard to over cal mag. I use 1ml per litre. The 700 scale is ppm by the looks of what he wrote lol.