EI vs Tap water

[Caliban07]

I'm not sure why but my water quality report is missing P, K, Zinc, cobalt and molybdenum so these will be excluded from this example.

The target ranges for weekly EI below compared with a weekly 50% water change which equals 40L. The micros are from CSM+B in this example.

Element EI Water change

Boron 75microg 240microg
Calcium 45mg 448mg
Copper 9microg 336microg
Iron 600microg 544microg
Mg 15mg 46.4mg
Mn 159microg 62.4microg
Nitrate 22mg. 45.2mg

As you can see a weekly 50% water change in most cases provides more nutrients than weekly EI targets and that is in my very soft tap water. Why do I need to dose anything at all.

Let's not for get EI targets are supposed to be non limiting i.e. 6WPG of light @ 30ppm co2

I have soil too....

My PAR isn't overly high 40-60 maybe.

If my tap water contains 10mg/l calcium (which it does) and I do a 40L water change technically i am adding 400mg of calcium. That should last the week right if EI (non limiting) targets 45ppm for the week.

Same with the other nutrients. Even nitrate @ 40L is equal to 45.2mg from the tap. EI targets 20-30ppm a week so I have more than this at the start of every week. That is without my fish load etc. Does this make sense or am I missing something?

 

[Caliban07]

Anyone [emoji1]

 

[Bill22]

Well I guess I'm anyone at the moment.

Your post went right over my head not knowing what you were referring to: it seems to be a very advanced post many might not understand. And I'm one(?)

Example:

The micros are from CSM+B

(???)

Quite enjoyed your serial tank setup post.

 

[Caliban07]

CSM+B is a micro nutrient dry powder formulated to provide certain levels of trace elements. There are many others that do the same. CSM+B is very popular.

When people administer CSM+B they target the iron level as this is the trace element that is needed most (apparently) the target for iron which would provide non limiting amounts is 0.2ppm dosed 3 times per week = 600micro grams.

The other non limiting amounts for all other elements can be seen down the EI column. This is the total at 3 x per week. 40L of my tap water provides the numbers in the water change column so my question is my tap adds nutrients that exceeds EI in most cases. EI (estimative index) popular non limiting dosing regimen.

Which post are you referring too [emoji846]

 

[kashif314]

I have no idea what you are asking really.

 

[Caliban07]

It's ok it's baloney. I got my maths terribly wrong. This thread should be ignored.

 

[flchamp89]

I think your onto something

 

[Caliban07]

I think your onto something

Apparently I can't do concentrations.

 

[flchamp89]

I had to convert your numbers and gave up last night lol

 

[Caliban07]

Basically, and it is a basic error.

I forgot to account for the 80L of water I was adding the amounts back in to.

In the case of Mg.

1.5mg/l (tap) x 40L (50% WC) = 60ppm/80L of water = an astonishingly low 0.75ppm magnesium.

This is more like a daily dose of PPS-Pro for 50% of the water changed.

Magnesium deficiency anyone?

Calcium would be about 5ppm and traces negligible.

Calcium is highest compared to other elements but is still lower than many taps. EI targets 15ppm weekly calcium.

Puts things in to perspective though. How source waters differ and the different troubles we face.

So if I add EI for NPK Mg and trace yet don't add calcium then the plant may not get much. Not just because Ca is low but it is much lower in comparison to other elements. Maybe soil has enough Ca and Mg?

 

[flchamp89]

Somewhere in threads I posted once about soil not all equal. I do alot of soil tests. Generally the better looking the soil is the lower the ca is but not always. Our sandy loam in much of Florida for example has typically high ca. But there been times ive gotten high ca.

When we buy soil for our aquarium it all different. Even when we say use mgops. The label on the bag from a chemistry stand point should be a guide. The label is based on their blend that has a registration number. Im sure there are variances even if all the bags were mgops.

You need to make your own Caliban lol