Prime?

[busdriver]

Does it hurt anything to use more than the recommended amount for water changes, ie:

1 cap for 50 gal. changing about 75 gal. of a 150, is it o.k. to add 3 caps? 

[audioslave_36]

I always use more than recommended, I have never had any issues.

[babblefish1960]

I cannot imagine changing out 50% of the water in anything other than an emergency. However, in answer to your question, if you are adding water directly to the tank, dose for the entire volume of the tank, and not just what you are adding.
Additionally, as the water treatment right now is on the heavy side, double dose for volume of tank, even triple if you see distress. It will be fine.

[busdriver]

Thanks!

[BigDaddy]

I cannot imagine changing out 50% of the water in anything other than an emergency.

It is part of Barr's Estimative Index Method

[darkdep]

I do 50% changes on my tanks if I go on vacation and they don't get changed in 2 weeks or more.

But then again, I don't keep any of those super fragile south american wussy fish.

[busdriver]

At least I don't have to worry about too much humidity!

Also, try to imagine how much a couple of hundred plecos cra* in a week.

[zapisto]

i was change 50% of my tank in all my dwarf tanks
never have issue and everubody know they was breeding like hell

i use double dose in my shrimp tank at the office.
what i observe , they have problem to breed (red cherry) ....!!!!
coicidence , i dont know.

[Zadig]

I cannot imagine changing out 50% of the water in anything other than an emergency.

Slightly off-topic, I know, but I agree with the above statement.

On-topic, Seachem's web site states, "To detoxify nitrite in an emergency, up to 5 times normal dose may be used." (source: http://www.seachem.com/products/product_pages/Prime.html)

It appears that using far larger than normal doses is acceptable.