JacksonL
Member
- Joined
- 27 May 2015
- Messages
- 120
Agreed, especially ones that may look like colourful sugary drinks to children. The blue nickel solution always looks thirst quenching 😂
-
You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up
Lean dosing pros and cons
- Thread starter Riverside Scaper
- Start date
Do I understand it right?
No matter how much CO2 we inject, we still have no CO2 when it is pH8 or higher. So no free CO2 available to plants.
And if we go further, is it correct to say, having pH7 after CO2 injection has only up to 20% of potential CO2 in water. Based on your chart in post# 650.
pH9 0% of CO2
ph8 0%
pH7 20%
pH6 60%
pH5 95%
pH4 100%
This may be one of the reasons why most plants are doing better in lower KH water. Because they have more available CO2 lower the pH is. Can this be true?
Maf 2500
Member
Highly likely to be one of the reasons, yes.
I think if you were constantly adding CO2 it would be impossible to maintain a ph of 8 and it would inevitably fall
Hi all,
cheers Darrel
Yes, I think that is where we are. I don't know enough about the chemistry of inorganic carbon (at higher than ambient CO2 levels) to give a definitive answer.
That would be my guess. I don't know what the practical<" limits of CO2 injection"> are (in a non sealed vessel) but judging by what happens, <"with even fairly flat, coke"> when you open the bottle I'm going to guess that you reach that limit relatively quickly.
That definitely true.
That is going to depend upon the plant, plants from harder water are going to be <"adapted to using HCO3- as their carbon source"> and will often be encrusted with calcium carbonate (CaCO3) via <"biogenic decalcification">. Plants from softer water won't be able to use HCO3- and may also struggle <"to uptake iron (Fe++(+)) etc">.
cheers Darrel
Last edited:
Wookii
Member
So the APFUK mix would be good enough but with the extra Mn (and Fe DTPA) - is the listed quantity of Mn insufficient then? Out of interest what are the deficiency symptoms of Mn?
Also regarding your point on the problem with CSM+B mixes, and getting an uneven mix of elements - if I’m mixing 30g in 2.5 litre of water for an auto-doser, I assume that’s not something I need to worry about?
Also the above analysis of the APFUK mix doesn’t mention Ni - should we be looking to include that also?
the deficiency symptoms of Mn is very similar to Fe deficiency for our aquatic plant, sometime it looks like the leaves are getting white spots/patches on them, but am not fully convinced if we could apply this 100% to our aquatic plant but this is what it looks like in terrestrial plant: Manganese - OMEX
0.02 ppm Mn might be sufficient under several scenario but I have given it a much more importance considering all the factors that I have discussed in this thread. 0.05-0.07 weekly is Sufficient even under high light fast growing plants. but this too will vary if your water quickly oxidize or precipitate the Mn.
the mix might be good enough but you might find yourself dosing more just to meet the Mn and Fe demand, which is needed and required in much higher amount compare to other Micros.
CSM+B, depends on where you get it from. Nilocg buy CSM and B separately and Mix them together later on, I believe he also use Borax rather than using Boric Acid, unless this has changed. even if you were mixing 30g or more, the ppm you are targeting for might be slightly off, Mo being the lowest ppm would be at the highest risk of being lower than the targeted ppm. if you were to clone the csm+b numbers with chemicals, I guarantee that you will get much better results compared to the original csm+b.
its up to you if you want to add Ni, according to the Science they are recognizing it as an important Micro Nutrient, also highly beneficial if dosing Urea as N.
if you look around you will find several thread on making recipes, use them as a guide and make your own and control them the way you want them.
Right, but I mentioned "when it is pH8 or higher". We are discussing CO2-H2CO3 relationship.
Maf 2500
Member
Yes. If you start with pH 8 or higher and inject CO2 the pH will drop because you are directly affecting the CO2-H2CO3 relationship.
Right, but we were trying to establish how large portion of C02 is available to plants at different pH values. For example, plants have no CO2 available in pH 8 if we inject CO2 or not. In pH7 only 20% of CO2 is available, in pH6 60%, in pH5 95% and in pH4 100%. Thanks to dw1305 we now know how this works.
Maf 2500
Member
Yes, I understand all that. What I meant was that the water will not stay at pH8 if you inject CO2, but will become lower and therefore a more hospitable environment for CO2.
I am not sure if we are actually disagreeing with each other or just talking round in circles?
Maybe some African cichlid keepers have tried injecting CO2? I feel it would still bring the pH down during the period of injection despite all the limestone and crushed coral and such that normally buffers the water.
ElleDee
Member
Maybe in this hypothetical there's a baking soda fairy sprinkling it in constantly to offset the acidification from the CO2.
Wookii
Member
I think that was Darrels point above though, that you will eventually hit the solubility limit for the carbonates, and will not be able to maintain the higher pH, so CO2 will always drive the pH down regardless.
Should be easy enough to test in a jug of water with some Carbonate/Bicarbonate and some injected CO2.
You agree there can be pH8 water with CO2 injection that was pH9 before CO2 injection? So no, the pH8 water with CO2 injection, in our case, is the final stage where pH8 remains with the CO2 injection. And this example is not fantasy, at 20 dKH we have 0.6 ppm CO2 at pH9, and 6 ppm CO2 at pH8. Doable?
GreggZ
Member
At one place I lived I had 20 dKH well water.
Fully degassed pH always measured at 8.2. If I drove that down to 7.2 CO2 concentration would be 37.98 according to the charts/calculators.
But I actually drove it down to 6.8. That would correlate to a CO2 ppm concentration of 95.4.
Just saying you can easily drive down 20 dKH water and have plenty of CO2 in the water column. And the CO2/pH charts graphs are not a reliable method to know how many ppm CO2 you actually have. Watch the plants and fish to optimize CO2.
In my current set up the charts/calculators would say I have 100+ ppm CO2. Do I really? I highly doubt it.
Fully degassed pH always measured at 8.2. If I drove that down to 7.2 CO2 concentration would be 37.98 according to the charts/calculators.
But I actually drove it down to 6.8. That would correlate to a CO2 ppm concentration of 95.4.
Just saying you can easily drive down 20 dKH water and have plenty of CO2 in the water column. And the CO2/pH charts graphs are not a reliable method to know how many ppm CO2 you actually have. Watch the plants and fish to optimize CO2.
In my current set up the charts/calculators would say I have 100+ ppm CO2. Do I really? I highly doubt it.
That's why I told you that any one you chose will be the best one. Reality is no one will be able to tell you with precision the requirement of each trace for each plant. That's also why they are called traces, as in we only need minute amounts. There are many people using APFUK without adding anything more in it and they are doing just fine.
Something also people seem to forget is that most if not all of those micronutrients are present in the soil as well if you are using a rich substrate like Amazonia or the like.
Hi all,
cheers Darrel
Yes that is it, it is how the <"drop checker works">. Because pH is both a ratio and a log10 value there <"isn't a linear relationship"> between pH and CO2 value, unless you stay in log10 values.
I think a one unit pH drop is always about 30 ppm CO2. I'd guess after that the log linear pH ~ CO2 correlation start to break down, but I don't know enough chemistry to actually say.
To get to pH 9 you need another base (other than CO3--) present, this could be <"dissolved oxygen"> or it could be the <"hydroxide ion (OH-)"> etc. The other way to get to pH 9 would be to have an atmosphere less rich in CO2, in which case the CO2 ~ HCO3- ~ pH equilibrium point would move up the pH scale.
Yes, you would definitely have some free CO2, but I'm not sure how much.
cheers Darrel
Last edited:
Wookii
Member
Sorry @Happi, still just trying to get my head around this. How did you work out the ppm values from the percentages that @John q posted?
Also, where do you apply the 0.02ppm MnSO4, to the weekly dose total, or the basic analysis above? For example, if we are targeting 0.4ppm Fe per week, Mn will be 4 x 0.022ppm = 0.088ppm - do we then add the 0.02ppm Mn to that to take it up to 0.108ppm per week?
Hi all,
cheers Darrel
<"Same for me">, unless we add enough to get <"into areas of toxicity">, the only difference is <"some", rather than "none">.
cheers Darrel
Fe 8.2 % / 1.603 = 5.115 ppm
then 5.115/0.1 = 51.15
then 5.115/51.15 = 0.1 ppm Fe
Mn 1.82% / 1.603 = 1.135 ppm
then 1.135/51.15 = 0.022 ppm Mn
Zn 1.16% / 1.603 = 0.723
then 0.723/51.15 = 0.014
do the same for others and you will get the ppm
Fe 8.2% 5.115 0.1
Mn 1.82% 1.135 0.022
Zn 1.16% 0.723 0.014
B 1.05% 0.655 0.0128
Cu 0.23% 0.1435 0.0028
Mo 0.15% 0.0936 0.00183
Fe 8.2% 0.1 (additional 0.05 Fe DTPA added)
Mn 1.82% 0.022 (additional 0.02 Mn added)
Zn 1.16% 0.014
B 1.05% 0.0128
Cu 0.23% 0.0028
Mo 0.15% 0.00183
Final:
Fe 8.2% 0.15
Mn 1.82% 0.042
Zn 1.16% 0.014
B 1.05% 0.0128
Cu 0.23% 0.0028
Mo 0.15% 0.00183
if you were to dose 0.4 ppm Fe weekly:
Fe 0.4 ( Fe EDTA 0.266 ppm, DTPA Fe 0.133 ppm)
Mn 0.112
Zn 0.037
B 0.034
Cu 0.0074
Mo 0.0048
this applies to POST #7
