SeaWater, premixed water at LFS?

I saw this stuff in a 5 gallon jug for like $8 and was wondering if anyone uses it.
I buy RO and mix my salt in a 5 gal bucket with a powerhead but are there benefits to buying it premixed such as sterilization, nutrients etc.
If I do the math and a bag of salt is $18 and my RO water is $1/5 gal jug am I saving money or is it more expensive?
OMG I am in developmental math at my university and the thought of configuring this makes me nauseous!
I don't mind mixing my own salt, I'm not that lazy. Just wondering if you guys have found it's better for the reef and it's levels. Thanks!!

 

When you buy it premixed you never really know whats in it... Your better off making it yourself in my opinion... I have bought mixed water that my LFS mixes themselves, but I knew them and trusted them.

 

Theres a conversion to determine the grams of salt for x-gallons at x-salinity thats easy, but annoying to type. I use kent salt and for ~4gallons I use 350-400g salt. So figure out salt per gallon, how many grams in a container of salt, and add the price per 5 gallons into the $1 per 5 gallon RO price. you can get a ballpark price that way without using exact numbers.

 

Before I bought a rodi filter for my house,it was costing me 50 cents per gallon to mix my own salt water. Kent salt-200 gal for $50, water-25 cents per gallon adds up to 50 cents per gallon, plus gas to get water. I prefer to mix my own anyway.
Matt

 

The bag makes 50 gallons, so (assuming ideal circumstances) the math is...

a. $18/50 + $1/5 = X (price of 1 gallon mixed at home)

b. $8/5 = Y (price of gallon at the store)

X = $0.36 + $0.25 = $0.61

Y = $1.60

You pay more than twice as much for the bottle and can't be sure of the quality control.

That said, I've bought them in the past in an emergency.

 

The convenience of having your own ro/di available for water changes or top off.......priceless! Well maybe not priceless but it sure is nice,and not that exspensive.

 

My LFS sells both RO/DI and pre-salt mixed RO/DI. The mixed is $1.09 a gallon, the non-mixed is 79 cents a gallon...and then my local Wal-Mart has an RO filter where they sell it for 37 cents a gallon.

Only having a 36gal tank I really don't have a need for a RO/DI unit, and its not worth the drive out to the LFS to get the pre-mixed.

 

Add in gas and time. you can pick up a nice used RODI for 150 ready to go and with the proper care will last a while. I use RO all over my house, even the cat gets pure water lol. Works really well in cooking too, no fluoride or bleach to mess with flavors.

 

I used 2 of these to start my 10 gallon reef because I didn't have a RO/DI system yet. I added a clown after the sand settled and nitrates went to 5 ppm and went back to 0 within a week.

 

I have one of those water towers like a block from my house and fill my 5gal jug for $1! I always keep one on hand and my tank is only a 30 so it doesn't take much. My bag of salt has lasted 2 mos. Was just wondering if there was any nutritional or biological benefits to using this store bought stuff.