When you say pH swings, just how much change are you talking about, and in what time frame, (a few minutes, an hour or two, 24 hours, every couple of days etc.).

The pH of the source water (even RO) can change daily. Are you talking about the pH as it comes out of the tap, or after the nutrients were added?

P.S. I'm sorry I don't remember from the other thread, what type of growing medium (and screening materials etc.) are you using?

Wonder where there maybe a friendlier more amature dumb down forum.
"Doing 10 with no Chance of Parole"

Did I ask the questions in a unfriendly meaner?

Often times some people feel a pH swing is simply a couple tenths of a point. And they become alarmed if this happens even 5 or 6 days after mixing the nutrients. I just wanted to get some clarification on the what the exact pH changes were. In the cases that I mentioned there is nothing to worry about, however if it goes beyond that, there may be a problem. the questions I asked weren't just for me, the answers will also help anyone that may have any potential advice (by giving them specifics).

If I remember correctly you mentioned that you used something to keep the growing medium (and/or roots) suspended. Some materials can affect the pH, that's why I asked that question also. And from your post' it wasn't exactly clear as to when when you took the pH measurements. Was it unfriendly to ask for clarification about that also?

What, do you expect great, exact, and accurate advice without providing any specifics on the situation? Do you ask your doctor how to make you healthy and well, then call him unfriendly or dumb if he asks about your symptoms? Or is your issue NOT with the questions, but just with me?

It's probably something in you municipal water that buffers the nutrient to a higher pH level.

Oh, no I just don't have a very good record keeping habit and kind of just wanted the general idea of why the RO in the first place, my plants seam to have better stem structure with tap and once established the pH seams to stay in area set more than RO although it takes more pH down. I'll go back to RO if there is a reason for it I can understand, you know just the general idea for now.
All new to us, just what we've read.
"Doing 10 with no Chance of Parole"

I'd guess calcium in the water based on the comment about better stem structure.

RO filters out many contaminants, tap doesn't. You can contact your local water company for a water analysis to find out what's actually in your water supply. Everyone's tap water is different, and with diffident amounts of different things in it (even in the same town).

The "simple answer" is most people use RO (or some kind of filtered) water because it's much easier to just use filtered water than it is to find out what's in your water supply to begin with, then try to adjust your nutrient solution to accommodate that. As for pH changes, it depends on what's in the water, as well as how much of it (that's the simple answer). And you can test the pH of your water supply daily, and it wont always be the same. That means that what's in it, and how much changes also (even RO water).

But because filtered water filters out many contaminants, there's less contaminants in it that would affect the pH. Also whatever is in the water supply may affect and/or react with the elements in your nutrients. The simple answer is most people use filtered water to avoid such problem.

Without any specifics other than the general statement that there is significant pH swing/change (that could mean anything). I have no way of telling if there's any problem at all anyway. I would assume if someone notes something they would call a significant change, they would have some sort of guesstimate on what the change they were noting was (otherwise how can you be sure there was a change in the first place).

OK the calcium maybe the answer to the stem firmness as our glassware gets a white haze that is impossible to get off. We are out in the county and the water company is using EXXON as a roll model. Over 40.00 a month for 3000 gal average use (why we quit RO) our livestock drink from the small lake on the property.
If we go back to RO is there a chart to know how much calcium to add for the good stem structure? Thanks
"Doing 10 with no Chance of Parole"

Regular tap water? No such thing. In fact, you have it completely backwards. The only thing you can count on being regular is the RO water. You don't know what the content of your tap is from day to day or week to week. This week you may have high levels of chlorine making your pH higher. Or higher levels of mineral deposits. Next week, the levels of either could be lower. After a major rain storm and some flooding (or a major snow storm and subsequent melt off coupled with a rain storm) you might find that the city has put out a boil order warning people that there could be tap water contamination. You might find that a company has illegally dumped waste into the nearest river because it is cheaper to pay the fine than to dispose of it properly in this bass-ackwards legal system we have. Seems to happen at least once a year or so in Indianapolis' White River. Or at least, we seem to be informed of it that often. I bet it happens more. You will also find more agriculture related contamination at certain times of the year. Worse, of course, if you have a well. Not enough to hurt you, usually, but enough to make chemical changes to the water.

In my experience, tap from my area leads to precipitation. I pay too much for micronutrients just to waste them with tap. Besides, cleaning the rez and lines is 10 times harder when you get all the deposits that hard tap water leaves behind. I don't use RO, though. I collect rain water.

I believe most nutrient charts/instructions out there assume you are using RO water. Purified water is the only thing you can use for a good baseline. So all of them tell you how much calcium to add for RO via the instructions for the micronutrient portion. It will depend on your plants, too, if extra is needed. If you want stouter stems, add a silica product. I started using it last year and tested it by only using it on one system. I was amazed at the difference.

Important to note: Calcium uptake is not usually diminished due to lacking calcium in the rez. Oftentimes, adding calcium will do no good. The nutrients usually come with enough and if you change your nutes regularly with the heavy feeders (like big tomato plants) then you will most likely have plenty. You just have to keep the rez cool enough and don't facilitate precipitation (such as by using high pH tap). If you use tap, be sure to adjust pH first. Then add nutrients. I believe (can't remember all my sources) it is recommended to wait 24 hours before adding nutrients to pH adjusted tap to make sure that the pH stabilizes and you won't experience excess precipitation of nutes. If you don't understand precipitation, please let us know and I'm sure one of us will get you a good explanation. I'm not on here as frequently as some, though.

You guys have been great. We have some decisions to make here and it is probable we will return to RO. This adventure into Aeroponics started with water farms from Growco and has led to this. When at there site and you go to Brand names on Nutrients the General Hydroponics that came with the water farms and is what we have stayed with. Low and behold there is no mention of Calcium in the Flora series. Their Organic Series does but not the Flora Series.
Thanks to u guys we now know.
We have ordered a nutrient chiller and will also get another RO system. One of the new ones that return 1/3 of the water. The ones we have now are something like 1/20, old units we have had since the 80's. I think it will be cheaper that trying to catch rain water although I love the idea of it.
On another note, trying to keep strawberries from freezing I have poisoned them with CO2 as we don't have the 220 volt lines run to the new green house yet for electric heat. Don't know how much damage we have done yet, if we're whipped out we just hope we can still get more bare-roots to restart our project this year.
Thanks again ,
"Doing 10 with no Chance of Parole"