I like that calculator! Its easy - almost. There are three or four buffers from their list that look like possibilities, but Im not sure I 100% understand how it works.
I am assuming the following:
Current Molarity = the molarity of the buffer already in solution? For RO water, that would be as low as possible? I set it to.001
Current PH - is actually the target PH you want for the final solution? Or is that the PH of the water your using to mix things up? It says to use distilled water, so Im guessing this is the target PH?
They say to use HCL (strong acid) or NAOH (strong base) to adjust the final PH. It looks like the two phosphates they are using in that example are salts then? Are these conjugates of each other?
One more question about that calculator - should I mix up an entire rez full of that mix before I add nutes, calmag, etc? Or would I only need to add small amounts to the RO in the rez?
They are salts being mixed together, so I would think the EC would go through the roof if I did a full rez with the amounts they suggest?
Ok, Im tired of trying to doing college level chemistry with the C- I got in 12th grade chemistry.=, so enough of that for now Im still arguing with myself, but I may just go back to tap (well) water until the AN PH perfect nutes get here or I figure out something else to try.
I have other issues that are starting to get pressing while I have been sidetracked on the PH snipe hunt. Another one of my nozzles is getting buried by fuzzy roots and a third one is not far behind. I cant think of anything else to do but raise them up higher and hope the roots cant get to them before I harvest.
The roots around the nozzles in back, that is now buried, dont look as good as other places, so I think that area is really feeling the lack of mist. On the other hand, they are still growing and are touching the sidewall of the chamber. Other areas are doing great - too great actually. But of course, other areas are still brown. On the plus side, the brown has not started a hard comeback like it did the last two times I stopped the copper - which is very good.
Im not sure I agree with Atomizer 100% on his inverted cone theory. Or maybe his theory is based on much better mist quality and/or more even distribution. So far, ever time I increase the flow rate too much trying to get the roots to grow DOWN instead of sideways, I loose all the fuzzies and get regular hydro roots.Even just s slight reduction in flow goes back to sideways growth and fuzzies. Lately, even the âwetâ areas seem to want to grow mostly sideways.
Ive decided that my âumbrella over the carpet matâ root system is actually doing just fine. The roots are drinking a much larger % of the water delivered by the nozzles the last several days. I am having to empty the runoff collection tray below the root chamber far less often than before. There is still runoff, but very little and evaporation seems to be keeping up with the runoff that gets to the collection tray. There is just a little left for the TDS monitor to work with. By the way, it is reading 550 on the input side and 820 on the runoff side. I suspect that is partly due to the increased flow washing stuff out of the roots - maybe.
Out of necessity, I have steadily been increasing the flow rate. In the last several days I have gone from 0.8/75 for 2.94 liters/day, down to 0.8/47 for 4,66 liters/day. Some parts of the roots look a tad wet, but many other parts are starting to look dry again, so I going to have to up the flow again soon.
Iâll look at that again after I re-position the two nozzles that are about to get eaten by the root monster.
Here are some recent pics. I know it didnt happen if there are no pics
Here is a comparison. The left pic is from before I added the 4th nozzle in the center to cover the âdead zoneâ. the middle pic is 2 days ago and on the right is today. Note the mat on the floor is much larger as well. You cant tell from the pic, but its climbing the sides of the chamber a little and getting thicker in some places where its nice and fuzzy - the white areas.
@anon32470837 i first want to commend you on an excellent thread, ive spend the last 2 days reading through your adventures here and your attention to detail and analytical problem solving are top notch.
mgso4 has good buffering abilities, but excessive amounts will lock out calcium. with my RO setup before i do anything, i add 200 ppm calmag, if not just straight mgso4âŚ
i know AN has a âph perfectâ nute line, something to look into maybe⌠or at least pull up the msds sheet and see what they are using as buffers.
do u keep your rez bubbling? co2 in the air dissolves into the water and will build up some carbonates, leading to a buffering effect.
on my RO system i put a valve on the discharge side and i run a 1:1 ro water to discharge, faster fill times, less waste water - and i replace my filters once a year to no ill effects.
Thank you sir! Thats a very nice compliment, but Im not so sure about the analytical problem solving thing. This whole PH business is kicking my ass and making me feel like the class dummy!
I will look into that. The Cal-mag Im using now is made from Magnesium Carbonate. I may try doing the cal-mag up to 200 PPM next time I re-fill the rez and see if that helps. Ive been keeping it down closer to 100PPM or a little less.
I just ordered some AN PH perfect stuff to try. It will be here Tuesday I think. The AN folks use MES (a $$ but very good buffer from what I have read) plus âother buffering agentsâ that I havent figured out yet. The MES seems to be the key one though.
Not bubbling, but I do have a 390 GPH pump in the rez that stirs and âflumesâ on a timer.
I have been thinking for a while that the C02 thing is at least a big part of my problem, I need to go back and re-visit that whole subject. I still dont understand the cycle well enough.
Plus I dont know what is really in my well water. I did finally get a report on water quality from the state earlier this week. I dont know how useful it will be yet. They test very intermittently and only do certain things each time - not a full panel of tests. That means that there are only maybe 6 tests that reference copper concentrations scattered over the last 15 years of sample tests. I just noticed that the report does have hardness, nitrates, and other things listed that may be relevant to my problems, but I need to go through and sort the data in the spreadsheet so I can see whats up. Thats on my to-do list for today.
Im running a series of tests now and part of that is to see if aerating or not effects PH. So far, it seems to have a dramatic effect in some cases - but - the results so far seem more confusing than helpful. Iâll report on that later. It will be 24 hours of testing later this afternoon.
Good to know. Im still running mine at closer to 1:2. I tried closing the valve on my discharge line, but it didnt seem to increase the outflow much at all, so I decided to play it safer. I suspect my low water pressure is my main problem. Its never over 50 PSI and closer to 40 most of the time.
My results on the tests I proposed above are in. I havent decided if this helps or not yet.
Ive been re-reading all the posts above and in particular the ones from @Northern_Loki. I also re-read the posts in this other thread on non-linear changes in PH.
Plus, I been Googling a lot - my eyes are crossed.
I think I am slooooooowly starting to understand some small parts of whats going on. Im now more certain than ever its a combination of my water hardness, and the dissolved C02 cycle almost everyone has mentioned.
The water test results I got from the state show my water hardness has varied over the years from 40 to 80 mg/L, but the most recent test was May 2016, so 2 1/2 years ago. It was at 73 in May 2016, In 2010 it was 42 and in 2001 it was 74. Based on how my water is acting, Im guessing its at least in the 70âs. I get scale on coffee pots, etc, so I know its somewhat hard.
Its my understanding that âhardnessâ is based on calcium and magnesium salts in the water. I also just read that RO systems have a hard time removing those particular things - especially the calcium, so my RO water probably has some hardness as well.
I have some test strips and they say the well water has a hardness of somewhere between 80 - 120. The RO water tests to around 40. Im not sure how much I trust these strips - they dont read chlorine worth a crap.
Anyway, it looks like I have somewhat hard water - even the RO seems to have some hardness.
The two most recent tests results show my well EC varies from about 93 to 175, but again, the most recent test was 2.5 years ago.
Ok, so I set up three samples plus the rez, plus water in the accumulator tank for a 24 hour test.
1) The rez was the same as always - about 2 ml/gal of my new CalMag at about 100 PPM (calcium hydroxide and magnesium carbonate), then mega crop to EC 1.2. The rez already had a small amount of PH up, plus a LOT of PH down in it, but I PHâed it back down to 5.4-5.5.
The only change I did to the rez was I stopped circulating the water and just let it sit for 12 hours. At that point I did a 1 minute stir, then let it sit again with no circulation. I did that to see if not stirring made any difference - it didnt.
After 24 hours, the rez was at 6.9 and the accum tank was at 7.0
2 was 1/2 quart of well water plus 10 drops of PH down which resulted in a PH of 5.7. After 24 hours = 7.2
3 was RO water with one drop of PH down = PH of 4.8. After 24 hours it was 6.6, but that isnt reliable. The PH was constantly changing in that one. I think not enough ions in the water to let the PH meter read accurately. I would put the meter in and it would start at 7 and drop to 6.5 one time, then start at 6.2 and climb to 7.5 the next.
4 was RO plus two drops of CalMag - zero PH up or down - plus enough Mega crop to get to an EC of 1.2. This one started at 5.5. After 24 hours it was at 5.7. One last hard stir/shake and it climbed to 5.8. That was 3 hours ago and its still at 5.8.
The RO plus calmag plus megacrop was the most stable - by far - even with some stirring and shaking.
Wild guess here - there is some thing going on between the calmag and/or the mega crop that has at least some small ability to buffer the PH on the low side, but not 100%. I am assuming that the C02 levels in the water are still causing some changes over time.
As a result of that, I just dumped the rez again, and re-filled with RO calmag and mega crop and nothing else. Not even chlorine. I read that chlorine has a tendency to raise PH as its very alkaline, so I left it out.
I put in enough Calmag to get to an EC of 0.3 or about 150 PPM. I stopped there because that was about 5 ml/gallon which is more than double the max recommended strength. Didnt want to go more than that - might be too much already.
So - we will see how this does over time.
Right now - with no other additives - the PH in the rez has settled to 5.6. It initially read 5.4, but I did a good bit of mixing and âflushingâ of the accumulator tank, and it now sits at 5.6 at exactly midnight. I will leave it now with no stirring and see what things look like in the morning.
Almost forgot one other maybe very important thing I noticed today. Every once in a while, I have been seeing fizzy water when I take a sample from the hi pressure side of the system - directly from the accumulator tank usually. I initially assumed it was trapped air in the system dissolving in the hi-pressure water, causing excess air to be dissolved in the water. When it comes out of the system, the air comes out of solution and forms tiny bubbles - like the fizz in soda water. I had a lot of that when the system was first put together, but it went away after a few days.
Ive dumped and re-filled the rez a bunch of times over a short period, and now the fizz is back. The question is - why?
My first concern was a ruptured bladder in the accumulator tank, but when I let air out of the fill valve, I get no mist and cannot feel any wetness at all. I was scratching my head trying to figure this out and after much thought and looking at things, I noticed that the pipe that feeds water from the rez to the vibration pumps runs slightly up hill. That would allow air to get trapped in the pipe when I drain the rez. I just re-did things to raise the rez a little higher and changed the slope of the pipe so that cant happen again.
Depending on how much air I have trapped in the tank, it may take a few days to get it all out. In the mean time, Im going to have unwanted dissolved air in the water in the system.
Im thinking/hoping that trapped air has been the reason the PH keeps going up after it gets pumped into the tank. The hi-pressure air will increase dissolved C02 and O2 and nitrogen, etc. Its a good theory for now anyway. I wont know about that for a few days.
The water drained out of the accumulator tank looked like weak muddy water at first, but it cleared up in a couple of minutes after sitting out in a container. Had me really freaking out for a bit
The new AN nutes will be here tuesday. Im curious to see how they do with the PH Perfect.
Long term, the AN nutes are pricey, so Im going to have to figure out a way to buffer the Mega Crop if this current test doenst work, or start mixing my own nutes with some sort of buffer built in.
The plants and roots are doing well - which is surprising considering the PH issues.
The plant looks great and is stretching nicely for the lights and bud formation keeps progressing. The roots seem happy enough with the new nozzle locations near the top of the chamber.
Im starting to wonder if most of my âbrown crapâ issues have just been due to under watering some areas. It all started early on after me forgetting to turn the timers back on at least twice in just a few days. I would be all in on that theory if it wasnt for the strong comeback and heavy growth spurt after every time I did copper.
Its seems clear that the brown means no fuzzy hairs. Its also clear that, once they turn brown, they never turn white again, not matter what.
The new white growth in the âdead zonesâ has all been new white fuzzy shoots coming in from the sides or from other areas, rather than the old shoots turning white again.
It is very hard to read the PH of pure water, first there are very few ions to be sensed, and it is also an insulator so static can throw out your readings.
âDue to the very nature of ultrapure water, you cannot simply assess the pH with a general lab electrode, which detects ions in the water to determine the pH. Pure water contains a low and unstable level of ions, making electrode reading unreliable â just one part per billion (ppb) H+ or 150 ppb CO2 is all that is needed to shift the pH.â
You may need to just add more crap into the water (specific crap of the sort you want) to make it less pure so you can get a stable PH.
This would explain why you only get a stable PH when you add CalMag and some nutes.
EDIT : From another site
âYour pH probe is having difficulty dealing with very pure water. Under these circumstances it may respond to fields around from equipment in the lab because it is effectively open circuit and acts like an aerial.â
I agree, The question is still - which exact crap to add? That last buffer calculator @Northern_Loki linked to is great in that it says exactly which chemicals to mix and at what concentrations, however, Im still unclear on which options would be good for the plants.
It seems to me that adding a buffer that also supplies magnesium and/or calcium would be optimal - since I always seem to need to add calmag anyway. But none of the ones in that link use those elements.
Well crap again. My newest test failed. This morning after 3 hours, things were looking really good. The PH in the rez had risen from 5.6 to 5.7, but by 6 hours it had gone up to 6.6, and the water in the accumulator tank was at 6.9 - and still fizzy.
The question I have now is why does the water in the rez behave so differently from the same exact water in a small container? The only thing I can think of is the ratio of surface area to volume is much higher in the rez because of its shape.
Sounds reasonable. Release the pressure (or increase the temperature) and the gas wants out = fizz. Now, the next question is whether that tank is using a bladder.
If it has a bladder, then there shouldnât be a whole lot of gas available to dissolve into the liquid. So, idk.
Although, it seems to be going in the opposite direction that one might expect.
Effect with the addition of bicarbonates (specifically to buffer the CO2) vs pressure:
Also, if this is the case, the effect should be reversible once the pressure is released and it has time to equilibriate <sic?> with the atmosphere.
FWIW, Iâm seeing about 0.5PH drift up in a solution of RO water + MC + kelp sitting in a bucket to 6.4. This is after adjusting the PH down twice. Seems it wants to buffer at something > 6.Though, this is not an âofficialâ test at this point. Just a premade solution for feeding the houseplants that I had measured after reading your comments. Also, there are some precipitants (as previously discussed by others in the MC thread).
One way to test this would be to have some plastic on the surface of the water so you can control the surface area exposed to air. If you see an effect with no plastic that is gone when using plastic you know that is the cause.
There is a lot of stuff here and am having difficulties tracking what is what. Could you re-describe the two tests? What is the small container, is that the mason jar?
That was a brilliant suggestion! I just PHed the rez and tank back down from 6.7 to 5.5 and covered 90% of the water surface with foam boards. We will see what happens this timeâŚ
HOWEVER - I was wrong about the surface area ratios between the rez and the samples, so I dont know what this will tell us. When I actually did the math, the small sample in the mason jar actually has somewhere around 1.5 times the surface area to volume ratio as the rez.
The mason jar was just over 1/2 full, so guess .6 quarts or 0.15 gallons. The liquid in my jars have roughly 9 sq inches of surface area when that full. So 9/0.15 = 60 sq in/gallon
The rez is 14"x23" when is it has 8 gallons in it. That works out to 322 sq in / 8 = 40 sq in /gallon.
So, another result that doesnt fit. I would expect the container with more surface area to exchange C02 faster and cause a faster and higher raise in PH - but Im getting the opposite result.
Im going to do the test anyway because it sounds like such a great idea and will give another data point.
Yeah, sorry I know this is hard to track. Im having trouble myself!
I did a new test. I mixed up several samples in mason jars roughly 1/2 full. I used RO and well water.
The only one that stayed close to its original PH was the RO + a few drops of calmag + Mega Crop at EC1.1.
In 24 hours it went from 5.6 to 5.7. That was WITH a good bit of stirring and shaking to aerate the water.
The rez - with a similar mix, (more calmag) went from 5.5 to 5.6 in 3 hours, then over the next three hours it went up to 6.6 - thats with no circulation or aeration. WITH aeration, it goes up faster.
When I PH it down after that, the PH in the rez goes up much faster.
I am fairly sure it not the bladder. I let some air out of the check valve and got no water or mist or dampness. Im hoping it was mostly the bad slope on the feed pipe to the pump that was trapping air in the system every time I re-filled the rez.
Your comment about temperature changes makes me wonder if that - plus my plumbing trapping some air in the lines every time I did a water change - could be enough to cause the fizz.
I have been changing the water in the rez faster recently because Im doing it so often with all this testing. My well water is colder now that it has been. It comes out of the tap pretty cold this time of year. I remember checking the rez temp on the last fill at 53F shortly after filling. My room temps are generally 67F or so.
Well crap again. Why cant I do things the easy way instead of bass ackwards?!?
Youâre right. My results dont fit my theory.
Ok, think I am starting to get a vague idea of how this PH/C02/weak/strong/acid/base thing works. Sort of. Almost. But Im not sure its helping much. I still have to many things I just dont âgetâ yet.
I had a major misunderstanding on alkalinity and PH. Im starting to get that alkalinity is a measure of buffering power - NOT PH. When I add PH Down or UP, I am changing the PH, but NOT the alkalinity.
When I add acid, it generates dissolved C02/carbonic acid - which is what lowers the PH.
But, then that C02 leaves the solution - out gasses - and the PH goes back up because the basic alkalinity has not changed.
The buffering thats going on with alkaline water is due at least in part to the carbonates in the water - which increase as the water gets harder. So harder water will be more alkaline than softer water - stronger buffering action on the UP side. Calcium carbonate seems to be the main one.
What I need to do is lower the alkalinity by changing the buffers in the water so the PH/pKa ratio is lower - down to 5.8ish rather than 6.6ish. .
Adding PH up or down is just chasing my tail and will get me no where.
So, if Im understanding this correctly, the PH raising in my rez is likely due to my combination of nute+RO still has a relatively hi alkalinity. When I add acid to drop the PH, its only temporary because the C02 generated will just out gass and then the PH will go back up. Adding foam to cover the surface of the rez should slow that process. We will see how that goes.
BUT - the PH raising in my accumulator tank is still unexplained. From all I know so far, it should either stay the same once its under pressure and sealed in the tank, or it should go down if there is excess air trapped in the system. BUT - it goes up instead of staying stable or going down.
Im still not clear on how the RO changes things other than removing some hardness. Does RO also lower the alkalinity? It must to some degree.
Im going to go re-read everything againâŚ
In the mean time, its clear that RO + Mega Crop + this brand of Calmag isnt going to cut it.
I need to come up with a safe way to lower the alkalinity and the target PH of the buffering action - in an affordable way.
Im really very surprised I have not seem any PH related issues with the plant yet. The PH in the tank has been swinging wildly every day for a good while now. Its been going from 5.5 - 6.7 over a short period of time, then I force it back down again. Rinse and repeat. The plant doesnt seem to care. It sure bothers me though
I think Im going to start a new thread on mixing custom nutes from straight chemicals and see where that takes me.
I have been graphing the PH of my tank (NFT recirculating) since I did a refresh on friday night/Saturday morning at mignight and initially, I needed to dose with PH down. I needed to dose every 1/2 hour for the first 12 hours then at lights on (Saturday) it shifted to every 1 1/2 hours then every 12 hours at lights off, Sunday I did not need to dose. Lights on Monday shows a sharper drop then a dose up at the end of the day. It looks like today there will be a dose up at the end of the day also.
One thing to consider is I hear many people running RO put 10-50% tap water into their tank to give some dissolved minerals and make PH more stable. I would imagine if you boiled your well water that would kill off any brown crap causing stuff and you would have some natural buffer in your tank.
Another thing to consider is, is your plant food designed for hydro or soil?
If hydro then it would be made to buffer at 5.5-6.2
If soil then it should buffer closer to 6.5-7.5 as these are the ranges nutrients are available in both mediums.
I did look at a megacrop ad but it just said âA wide variety of mediumsâ which sounds like they would aim for a PH over 6.5, as this will allow growth in hydro as well as soil (hydro has a little spot just over 6.5 where you donât get deficiencies but growth is not as good)
This is all very interesting. I am still waiting on the spigot install in the room before I will get my RO hooked back up, but once I do I will throw my data in the mix with you. I had a wild pH ride with RO last time too, so hopefully we can compare notes and find a good solution.
Im still arguing with myself, but I may just go back to tap (well) water until the AN PH perfect nutes get here or I figure out something else to try.
