Dosing questions, calculating PPM, and transparent leaves

[simpsonian]

I've done some research and just recently started a 55-gallon planted aquarium with an assortment of plants and some shrimp and snails to help with any algae outbreaks. I'm starting to evaluate my ferts and dosing and want to make sure I have the fundamentals right.

Firstly, I have well water and a water softener and I believe this removes most of the minerals from my water. I am not injecting CO2 and have the Aqueon 48" LED with 2 light strips (Amazon.com: Aqueon LED Aquarium Light Fixture, 48-Inch: Pet Supplies) that I believe should be adequate for my low-tech setup. I planted my aquarium last Tuesday and did not add any nutrients. By Saturday the plants were looking sad with leaves turning clear and some wasting away. I did some research and most pointed towards an iron deficiency. I have since done a 50% water change and added Flourish Complete (5ml daily starting yesterday) and API Leaf Zone (25ml weekly, starting yesterday). The plants seem to be recovering but I want to make sure I'm not missing something. I have also read that with a low-tech setup dosing Macros was not necessary. It would be great if anyone could give input here to let me know if I'm on the right track.


Now, regarding dosing ferts, can someone please confirm that I’m calculating this correctly? I’m trying to understand how much a certain dose of fertilizer will raise the PPM of that fertilizer in my tank.

For my example, let’s use a solution of 10% Iron chelate to raise the amount of iron in my tank.

1 ml "x" / 1000 L = 1PPM "x" --> +1 ml Iron / 1000 L water = +1PPM iron

+1 ml Iron = (10% Iron)*10 ml solution

+1ppm iron = (10 ml solution) / (1000 L water) * (189 L water) / (1 aquarium) = 1.89 ml solution/aquarium = + 1 ppm iron / aquarium

Does this make sense?


Hoping the experts here can impart some wisdom!

Thanks!
Caleb

 

[fort384]

It sounds as if you are on the right track. I would still be concerned about those LEDs and whether they will support growth in that deep of a tank, even for low light plants. A 55 gallon tank is pretty deep to use what I assume are less than 1W diodes (though I could be wrong on that, but I don't see any specs on the diodes on aqueon's website).

Let us know how it goes.

 

[simpsonian]

yes - i am concerned about that as well. I think I will add one more strip to max out the lights. the LED's are just so cool and quiet, not to mention their low profile and nice blue night light! Some reviews on Amazon have said they work well for med/low light plants but time will tell. I pruned off the damaged leaves this morning and I think the plants are looking more healthy.

Caleb

 

[aqua_chem]

What plants do you have? That sounds kind of like crypt melt to me.

 

[aqua_chem]

Also, your math is wrong.

1 mg / 1000 g = 1 ppm

But since 1000g = 1L of water (ish)

1 ppm = 1mg / 1 L

Now the issue of ppm is that it's all relative, so you need to know the actual units of each measurement.... unless you use something like this instead.

 

[simpsonian]

I understand what you are saying but my 10% iron solution is not measured in mg - it is a liquid of 10% concentrate. If it is 10% by volume (not weight), can't I use 1mL/1000L for PPM? 1mL of a chemical in 1000 L of water must be literally 1 part per million...

1 mL / 1,000,000 mL = 1 PPM, right?

 

[aqua_chem]

Where did you get the iron mixture?

 

[mwampoki]

Assuming that your iron solution is indeed 10 % by volume and not by mass, your initial post was correct in the way that you figured it. If your solution is 10 % by mass, Aqua_Chem is correct it really depends on which way your solution was made. If it was made 10% by mass, you would need to figure out if it was made by using 10% of the mass of Fe in the solution of the total mass of the Fe plus the chelates used to make the metal soluble.

 

[simpsonian]

great - thanks! the PPM question was more of a theoretical one to make sure I understand how it works. I'll have to make sure I understand whether the concentration is based on mass or volume or just use the on-line calculators. i believe most mixtures are based on % mass which is why some of my test calculations were not matching up with the online calculators.

what i'm hoping to do is find my ferts to use and develop a spreadsheet that tells me exactly how much to add when I input my current levels. I know this can be done via the on-line calculators as well.

 

[aqua_chem]

You still need to measure it in mg/kg. mL/1000L doesn't work out mathematically in this case because the densities are different. Also, you don't measure solutions made of anything solid in vol/vol because you can't measure the volume a homogeneous mixture like a powder, only the mass.

Also, depending on what chelator you use, a 10% solution of iron chelate will only have 10% (+-3) iron, so a 10% solution of 10% chelate will only be 1% Fe, although I'm still extremely dubious of how you made this solution.

 

[simpsonian]

ok - thanks for clarifying and I will make sure to use ppm by weight.

 

[aqua_chem]

It's pretty easy if you convert it all to mg/L (in water), and then do the percent iron conversion. The calculators are usually pretty nice as well.