Want more accuracy? Want daily PMDD style EI dosing?

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Tom Barr

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Adding 1/2 tsp of Ca and 1/2 of Mg ought to do it 2x a week.

Regards,
Tom Barr
 

rthomas

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Oct 25, 2007
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I guess CaCl2 would also be able to do the job.

Thank you Tom for all your input.
 

Tom Barr

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Folks have used that, it does dissolve fast. CaSO4 seems better to most, however most folks cannot tell a difference or have done such test.

SO4 vs Cl, I'd chose SO4.............but that's speculation, not fact etc

Regards,
Tom Barr
 

rthomas

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Tom Barr;20244 said:
Adding 1/2 tsp of Ca and 1/2 of Mg ought to do it 2x a week.

:eek: excuse me Tom, but don't you think that is under dose for a 160g tank with CO2 injection? I am afraid my pH would be too acidic.
 

danbryans

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Tom Barr;17838 said:
This is an example of EI for a 12 week supply for a 20 gallon tank for those with teaspoon adversion.

To 1 liter of DI water add:

60 grams KNO3
18 grams of KH2PO4
25 grams of GH booster

Add 12 mls daily.
Add TMG at 2.5 mls daily.


Hi tom.. just would like to know how much K (in the GH booster only) is being dosed using the above mix at 12mls daily for this 20gal tank?
 

Tom Barr

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rthomas;20249 said:
:eek: excuse me Tom, but don't you think that is under dose for a 160g tank with CO2 injection? I am afraid my pH would be too acidic.

Adding this should not influence the pH. They are not Carbonates.
You can add more if you wish, but the plant's actual need/demand is not that high really.

I used CaCl2 for some time but felt CaSO4 worked better, but I have no such evidence, namely the effect of Cl- ions vs SO4-, the latter I know does not cause any plant issues.

But folks use KCl a lot also without issues as well.

So.........

Mg and Ca are also present in the Tap if you have a GH of 2 or higher.

You mention a KH of 2 degrees and seem to have it mixed up with GH?
A low KH does not matter much. Folks say you should have a KH of 3 or so etc.
But even a sub 0.5ppm HAS NOT BEEN AN ISSUE. This is much lower than 0.5 degrees!

As long as there's enough CO2, the KH is not an issue. Many folks have a KH of 2 and do not bother with adjusting it.

Just leave it and know things are nice, you have decent soft water.

In the end, I'd likely just get some GH booster, it's pretty cheap and specific.
I'd add 1.5 teaspoons 2x a week, once after the WC and again at 3-4 days in.

Much like individually dosing Trace metals, I just put the GH all into one group that's balanced and dose that.
You can do the same for NPK also.

So if you really wanted to make 3 basic liquids to dose:
NPK
GH
Traces

Some want a bit more manipulation with NO3 and PO4.
That's easy enough to play with by separating them out.

Regards,
Tom Barr
 

Tom Barr

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danbryans;20252 said:
Hi tom.. just would like to know how much K (in the GH booster only) is being dosed using the above mix at 12mls daily for this 20gal tank?

I'm not sure, I do not make GH booster:)
Nor is it an issue, I suppose I could test for K+, but as long as I have excess relative to N and P, which I must based on the ratios of KNO3, and some additions from KH2PO4 and the Gh booster, I most certainly have excess K+.

I know,because I've tested in conclusively, as long as the K_ is above say 10ppm, I'm okay, I've gone to 50 ppm critically without ever seeing an issue in the most sensitive plants.

So that's a huge range.

You can ask the maker about GH booster.
It's likely about like Seachem Eq, but less K and more Mg.

Regards,
Tom Barr
 

danbryans

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Jan 24, 2007
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Tom Barr;20258 said:
You can ask the maker about GH booster.
It's likely about like Seachem Eq, but less K and more Mg.

Regards,
Tom Barr


err...sorry 'bout that. :eek: And thanks for the response. :)
 

Tom Barr

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this is not rocket science here, it's just simple farming of plants, you do not need nor require precise measures of K+, Ca, Mg, etc.

You just need to know you have enough to be non limiting.

Now some want to reduce their levels down to the minimums, then you start having to monitor things much closer. But having a bit extra in the non limiting level causes no negative effects either.

Regards,
Tom Barr
 

rthomas

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Oct 25, 2007
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Tom Barr;20244 said:
Adding 1/2 tsp of Ca and 1/2 of Mg ought to do it 2x a week.

Regards,
Tom Barr

Another issue Tom. :confused:

I can only get Calcium Nitrate Tetrahydrate Ca(NO3)2.4H2O . Adding 1/2 tsp of that and another 1/2 tsp of Mg after WC to my 160g tank. Now I am not sure how much KNO3 I should use after WC. I think I surely must use less KNO3 bcos some NO3 are there in my Calcium Nitrate.

But I am not good in Chemistry. Appreciate your advice on the amount of KNO3 to use. TIA.
 

Tom Barr

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Well, if Ca(NO3)2 is all you have avail, then you can use about this same amount, but use about 60% of the suggested KNO3.

You only add some Ca(NO3)2, once a week.
I'd try and get CaCl2, or CaSO4 if you can, it'd be odd if all you can get is Ca(NO3)2.

You can use it, but I'd likely use /add K2SO4 if that's all I had available for Ca to add to the K+.

So on WC day, I'd add about 3/4" tsp Ca(NO3)2, and 1 teaspoon K2SO4.
No KNO3.
Add about 1/2 teaspoon epsom salt 2x a week.

But after, until the next water change, KNO3

Regards,
Tom Barr
 

rthomas

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Oct 25, 2007
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Tom Barr;20583 said:
So on WC day, I'd add about 3/4" tsp Ca(NO3)2, and 1 teaspoon K2SO4.
No KNO3.
Add about 1/2 teaspoon epsom salt 2x a week.

But after, until the next water change, KNO3

Regards,
Tom Barr

Tom, I don't speak and write English very well. Let me see if I can get this right. I will normally do my WC on a Sunday, so

Sun: 50% WC, 3/4 tsp Ca(NO3)2, 1 tsp K2SO4
Mon: 1/2 tsp MgSO4, TE
Tue: KNO3
Wed: 1/2 tsp MgSO4, TE
Thu: KNO3
Fri: TE
Sat: rest day, enjoy watching the tank. Good time to look for any deficiency

For my 160g (approx 600 litre) tank:

1) Am using CSM+B, how many tsp TE ?
2) How many tsp KNO3 ?
3) I don't see any reference to KH2PO4. How many tsp should I add, if any?

TIA and warm regards.
 

rafel

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Oct 24, 2007
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Roger,
I would go along the target ppm and work backwards to get the amount of macros that you need.

Targets are:
25 - 35 ppm NO3
10 - 30 ppm K+
1 - 2 ppm PO4

And you are using Ca(NO3)2 to add calcium and the normal macros like KNO3, KH2PO4 and K2SO4.

If we go along Tom's suggesstion of adding 3/4 tsp Ca(NO3)2 and 1 tsp K2SO4 after every WC to your 160g tank, we'll have (with Fertilator):
4.73 ppm NO3
4.74 ppm K
1.01 ppm Ca

Looking at the target values, you are short of
25 minus 4.73 = 20.27 ppm NO3
10 minus 4.74 = 5.26 ppm K+
and 1 ppm PO4

Now you need to divide those figures by 3, because you are going to dose the macros 3 times a week (or daily, then adjust accordingly).

20.27 divide by 3 = 6.8 ppm NO3
5.26 divide by 3 = 1.8 ppm K+
1 divide by 3 = 0.3 ppm PO4

So how many grams or tsp of macros do you need to add to your 160g to get those ppm levels?

Again, with Fertilator, it showed that you need to add
1) 6.8g (about 1.25 tsp) of KNO3 3 times a week

2) BUT with that 6.8g of KNO3, you are also adding 4.34ppm K into your tank. And 3 times a week will add 13 ppm K into your 160g tank. Adding that to the amount that we add after WC, we get a total of nearly 18 ppm K+ in a week.

3) 0.26g of KH2PO4 3 times a week (will also add 0.12 ppm K)

As mentioned by all our Plant Guru, this is no rocket science; but like many others, I would go thru all those calculations just as a note so that I won't stray too much :D

Anyway, it's great if our guru can confirm my calculations. TIA.
 

rthomas

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Tom Barr;20583 said:
So on WC day, I'd add about 3/4" tsp Ca(NO3)2, and 1 teaspoon K2SO4.
No KNO3.
Add about 1/2 teaspoon epsom salt 2x a week.

But after, until the next water change, KNO3

Regards,
Tom Barr

Tom, what exactly do you mean by "But after, until the next water change, KNO3" ?

BTW, I don't see any reference to KH2PO4. Would this be okay ?

Sun: 50% WC, 3/4 tsp Ca(NO3)2, 1 tsp K2SO4
Mon: 1/2 tsp MgSO4, TE
Tue: 1 tsp KNO3
Wed: 1/2 tsp MgSO4, TE
Thu: 1 tsp KNO3
Fri: TE
Sat: rest day, enjoy watching the tank. Good time to look for any deficiency

Or should I cut the KNO3 on Tuesday and only dose it once on Thursday ?
If KH2PO4 is needed, 1/4 tsp 3 times a week ?

Please advice, TIA and warm regards.
 

Tom Barr

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You have a 160 Gal tank.

Add Ca(NO3)2 on the water change day, the rest of the week, add KNO3.

PO4, TE, Etc.......you do as you where doing.
All you are doing is adding more GH on the water change day is all.
Ca and Mg.

You get plenty of K+ from K2SO4.

This way you can add more Ca, without having to add Ca(NO3)2 all the time.
You can if you want to, and also add K2SO4 along with Ca(NO3)2 and not use KNO3 at all.

Up to you and how much Ca you want.
I use CaSO4 namely for additions of Ca.


Regards,
Tom Barr
 

rthomas

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Oct 25, 2007
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Tom, you have been very helpful. BTW can I safely use this chemical called Plaster of Paris ? Someone told me it's Calcium Sulphate, CaSO4·0.5H2O , Plaster - Wikipedia, the free encyclopedia .

If your answer is yes, then I figure it will be 1/2 tsp of that CaSO4·0.5H2O and another 1/2 tsp of MgSO4 after a 50% water change?
 

Tom Barr

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I believe the pp is CaSO4.
I also know it as gypsum, I'm more inclined to get it via that way, but if it's 100% CaSO4, or close, then use it, especially if very fine ground.

It does dissolve but takes more time than say CaCl2, but it's a lot more soluble than CaCO3.

Yes, that amount should relieve most any issue you have with GH, dose that amount 2x a week.

Since this thread is about using the PMDD liquid dosing method, generally daily, add 2 teaspoons of CaSO4+ 1 tsp of MgSO4 per week's worth of dosing.

Note, since it's less soluble, as is K2SO4, plus you have a larger tank.......you may consider using a larger volume, say 2-5 liters at a time for a 2-4 week batch for the macro's, and 500mls for the traces.

The confusing thing and at the same time the flexibility here is that you can customize the solutions to meet any goal or demands you desire for the tank.

This is one reason I went to EI type of dosing suggestions for folks, simple made it easier for folks.

There are trade offs, but not that many relative to the usefulness.
Same with any approach.

Regards,
Tom Barr
 

rthomas

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Oct 25, 2007
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Tom Barr;20720 said:
Since this thread is about using the PMDD liquid dosing method, generally daily, add 2 teaspoons of CaSO4+ 1 tsp of MgSO4 per week's worth of dosing.
For a 160g (600 Litre) of water, that will only give (with Fertilator) 2.83ppm Ca and 0.16ppm Mg. I have read many times that the target ppm for Ca and Mg are 10ppm and 2ppm respectively. Reason for this Tom?
 

Tom Barr

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Don't you have some in your GH?
Have you tested it for Ca and Mg specifically?

Mg can be added as needed, but you really do not need a lot, and adding that much per day is fine unless you have a lot of light/CO2. TMG also has some Mg as well.

If you know how to get the ppm's, why are you asking me?
It sounds like you have a certain notion of what the range should be as it is...........
so do that.

It's not going to hurt.

However, I've never suggested 10 ppm of Ca and 2 ppm Mg anywhere ever.
So as far as "optimal", that's rubbish.

I've done a rather exhaustive survey of Mg and Ca mineral content in aquatic plants, about 3-4: 1 ratio is what's found in them. They have the same levels whether or not that external Mg is 0.1 ppm or 2 ppm or even 52 ppm like our well water at the lab etc or in in natural systems, same for the most part with Ca. I wrote 15 pages about it on the Barr Report newsletter with supporting details and primary research references.

External concentrations can vary widely, and we see excellent growth with both high and low GH's in aquarium plants.

My reasoning for telling to add little is to see if it's limiting.
You should see a dramatic response if so.

If not, perhaps you have enough from the tap already...........
So it's one issue you may not even need to worry about, but if you feel 10ppm Ca and 2 ppm Mg is what you want, you seem to know what to do already.

Higher GH's will certainly not hurt.
I prefer them fairly high myself, about 5 or higher.

I use the GH scale and add extra mix of a known ratio of Mg/Ca together.
That's easier than messing with specific Ca and Mg ppm's and does not even matter what the individual Mg/Ca levels are since the added extra is at the right range.

Adding 5x more Ca and 10 x more Mg is fine and if that's your target, go for it.

Regards,
Tom Barr
 
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