how long will flourish last

[ttan]

I read on the bigals that they had a 2l container of flourish for ponds, for like 21 bucks, which Is the same as regular flourish. It said that 100 ml treat 5000 gallons. I've done the math as for how long it should last, and even at dosing at twice a week, it seems that it'll last a very very long time. Its pretty late here and so its seems rediculous that it would last as long as I think, so I'd feel better if someone can confirm this. I have a 29 gallon tank. So a 2l container treats 100,000 gallons. so I could add it to my tank 3448 times. and lets say I dose it twice a week, so 1724 /56 week per year= 30 years? I just checked the math, but doesn't seem right, I mean seachem wouldn't be making much money that way. Where is the catch?

In case you couldn't figure it out, I am procrastinating on a 20 page paper that needs to be bound due tomorrow at 1 30

 

[kveeti]

Seems ok, but math isn't my strong point.

However, 1 year = 52.177457 weeks.

I know I just buy a 250 mL bottle of the stuff for my 28 gallon and it lasts a LONG time. The bottle says "250 mL treats 100 gallons for 4 to 6 months".

 

[Hannys_Papa]

Considering that i've read that you might want to keep it cold or in the fridge after opening it (i think its to prevent it from getting moldy) i am sure there is also some kind of ageing of the product involved. So after 15 years the 2L bottle of flourish might not smell/ look (lol) or work as well anymore as the fresh product.

 

[ttan]

wow , yes there are 52 weeks in the year. I was tired last night, but at least I got it in the ballpark of 52. good points about the molding. I was going to buy dry powders and make my own fertilizer, but after seeing how long this stuff will last theoretically, it didn't seem worth the effort. Thanks guys