Ok...math help for ferts

[twoluvcats]

I want to dose my tank with Flourish Excel...I read the directions and think I've figured out how much to put in, and then I see the big BOLD warning "DO NOT OVERDOSE" ACK!! lol so now I really have to be right!! hehe

here's what's on the bottle:

On initial use or after a major (> 40%) water change, use 1 capful (5 mL) for every 40 L (10 gallons*). Thereafter use 1 capful for every 200 L (50 gallons*) daily or every other day. Dosing may be slowly increased in high-growth aquariums. For smaller dosing please note that each cap thread is approximately 1 mL.

I have ~25g in my 29...how much should I dose for initial and maintenance? Translation to tsp would be the best for me, but I'll take what I can get. Also, what about dosing 8 gallons (in the 10g tank).

TIA

[amanichen]

How accurate is your measuring equipment? Can you measure down to .5ml, .25ml or .125ml?

[twoluvcats]

actually, yes i think i can...I have a baby medicine spoon that is marked in pretty gradual doses...I never used it for my daughter...so I'll add it to my "fish-stuff"

[amanichen]

I won't post all the math here, but here are the results. The gallon to liter conversion that seachem lists on the bottle is significantly off from the actual conversion. Since chemists use SI units I kept everything in SI until the very end.

Vi is the initial volume of fluorish, and Vm is the maintaining volume of fluorish, used for a dose.

@25 gal
Vi = 10.929 ml
Vm = 2.366 ml

@8 gal
Vi = 3.4974 ml
vm = .75708 ml

Now, you won't be able to reproduce these exact amounts, but if your measurement devices are accurate to .125ml then here are the numbers you want:

@25 gal
Vi = 10.875 ml
Vm = 2.375 ml

@8 gal
Vi = 3.500 ml
vm = 0.750 ml

If your devices are accurate to .25 ml here are the numbers to use:

@25 gal
Vi = 10.75 ml
Vm = 2.25 ml

@8 gal
Vi = 3.50 ml
vm = 0.75 ml

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EDIT: If your measuring device has marks every 0.5ml, then you can measure with an accuracy to the nearest 0.25ml. If your measuring device has marks every 0.25ml, you can measure with an accuracy to the nearest 0.125ml. Etc...
=====================

These are slightly rounded down, but they're more accurate than the conversion that seachem implies on the bottle. I want you to know that what seachem lists on their bottle gives you a proper dose if you measure your water volume in liters, and a slight underdose if you measure your water volume in gallons.

Seachem says:
40 liter = 10 gallon
Actually:
40 liter = 10.5668820943259 gallon

My calculations reflect the actual conversion, not the approximate one. This is probably more than you ever wanted to know, but I have an excuse...I'm an engineer, I do stuff like this for a living.

[twoluvcats]

My calculations reflect the actual conversion, not the approximate one. This is probably more than you ever wanted to know, but I have an excuse...I'm an engineer, I do stuff like this for a living.

hence the reason why I asked here...I knew you'd come thru

ok now wait...I'm confused...on the vm dose for the 8 gallon you have 2.366 then 3.375 then 2.25...is the 3.375 a typo?

[amanichen]

Typo...hrm...probably =)

All the goobly gock above is measurement theory...I took a class that included it a year ago, and it's since been burned into my brain.

[twoluvcats]

ahHA, now that makes more sense