RO/DI? Worth it?

[jeg]

Quick question. I have a 37 gal. reef. I have very little evaporation. I am doing small water changes once a month. What would be the best option for water. I have been using tap, but my phosphates are out of control. Any thoughts? I really dont want to spend the money on an RO/DI unit for the small amount of water I would need to use it for.

 

[jeo]

Find out if there is anywhere you can buy RO/DI water from. I know our Walmart sells it for $0.66 a gallon. Something to look into anyway

 

[jeg]

LFS sells it for .99 Its an option!

 

[broomer5]

You say "very little evaporation" HOW MUCH ?
"small water changes once a month" HOW SMALL ? GALLONS ?
"small amount of water I would need to use it for" HOW MUCH FRESHWATER DO YOU USE A MONTH ?
Once you know this - it's much easier to decide if you should spend money on an RO or RO/DI unit.
37 gallon reef tank example:
2 gallons a week top off for evaporation = 8 gallons per month.
10% water change per month = Aprox. 4 gallons per month.
12 gallons/month
Say 150 gallons per year as an estimate.
Now how much can you buy RO water for - and trust that it is good ?
To me - even a low output RO unit is better than having to run to store and haul water jugs back and forth.
Plus if you need it you make it.
Simple.
But I realize that not everyone want's to fork out the upfront cash for a unit.
I feel it's justified doing so.
Only looking at first year for comparison.

 

[jeg]

broomer...good points..You are pretty close with the weekly/monthly estimates..Its confusing. There are some many different types of units out there. How long does the membrane last? What parts need to be replaced?

 

[tropicalreefs]

You can buy a unit for anywhere between 100 and 150 that will do a good job. If you are buying water from a store at .35-.99 and are doing say 10% water changes and evap top off lets just estimate 5 gallons a week, an RO or RO/DI will pay for itself pretty quick. I have an RO that I spent 200 on and I use it for cooking, drinking and my tanks. I've had it for 3 years and just ended up changing my membrane a couple of weeks ago. Membrane was 70 and the replacement filters (I have a 5 stage) was 50 total. I change the filters about once every 6-8 months. It's a good investment IMO.