RODI water. Does anyone get it free?

[Greg P]

A decent rodi unit runs about little over $100 and prob costs less than $100 per year in filters. If you are able to install it, is a no brainer.

To add to the thought about costs;
My tap water runs 7-12 TDS. Yes, it's that low.
My RO only unit was around $130, 6 years ago.
I've only replaced the Membrane once @ $80 due to my mistakes of not flushing the unit properly. Should have lasted me 5 years.
I spend about $50/year in Carbon and Pre-filter blocks. I change my carbon block every 6 months and my pre-filter block every 3 months, regardless of gallons used.
I use a Carbon block for Chlorine, not Chloramines, so my filters cost me about $8 each; both carbon and pre-filter.

I go through about 300 gallons/month of usable water with flushing the RO system, water changes and top off water. With my RO modifications, I use about 600 gallons/month for my saltwater tank.
Yes, my RO system gives me 1:1 production, roughly, give or take a few gallons here or there.

I run a Vertex RO unit with a (current from my LFS) Dowtech Membrane.
I have installed a custom bypass flush valve resembling this to flush the TDS before making new water.

I use a 75GPD Membrane, and a 75GPD flow restrictor.
I've measured the water coming out my waste water line and my RO line after the Membrane.
Maybe it's not a true 1:1, but it's awfully close. And that's with my city water pressure of 60-65PSI with me adjusting the regulator.
I don't want to push it higher as the house plumbing is over 40 years old.
Regardless, it's nothing like the 1:3 or 1:4 units I've read about.

Regardless, using the flush valve is a big plus to keep your Membrane clean.

So, my annual cost so far is about $85/yr for 600 gallons

My LFS states my Carbon block is good for up to 3,750 gallons and I use about 3,600.
The Pre-filter is not rated and I change it out every 3 months as that's about when it gets brown.


Maybe I should check my production again, but last time I checked it was 1:1

 

[Sashaka]

I don’t own the property buts it’s public and not far from my house.

i don’t have a LFS. I just figured I hated buying salt all the time so I started just grabbing sea water. Hasn’t been an issue in the 7-8months I started using it. But I still need to top off. Which I buy, but don’t have too....

I would never add lake water or another open source of water to my saltwater tank. I know many pathogens and bacterium don't necessarily transfer well from fresh to salt and vise versa, but it's not worth the risk of introducing some pathogen or some other hidden organic or metal into my tank. I've done the whole tank gets sick thing more than once. It's no fun.