Eheim Liquidoser for dosing additives?

[mahalamata]

I came across these the other day and seem like a nice simple and cheap way to dose calc and alk additives to a small tank.I have a 20g nano and these thing apparently dose 1ml per dosing and can be programed to doe several times a day.So my thought is 1ml a day would prob cover my weekly 6-7 ml doses.Also it would add it progressively over the week as opposed to adding them in one go.I have not seen anyone here use these so was wondering if there is a reason for this I am missing...or is my idea a good one??

http://aquarama.co.uk/product_info.php?products_id=550

link to product..

[mahalamata]

sooo....
no one has tried these?no ideas?

[Donw]

They dont really hold enough. It wont be long before you surpass the little bit it holds in a single dose, even in a 20. IIRC they only hold 80ml.

Don