RO/DI System??

TPetty84 · Feb 26, 2014

Hi all!

I've been throwing the idea around of getting an RO/DI system of my own. I'm currently setting up a 24 gal Aquapod, and MAY get a large tank sometime in the future. Locally, I can get 5gals of RO/DI water for around $4. My question is, with a tank this size, would it be worth my while to invest in my own system? I have no experience with them at all and don't know what to look for. Do the filters have to be changed often? Any info would be helpful. Thanks!!

Tim

reefndude · Feb 26, 2014

Air, water, and ice makes some nice units. Filters would last a long time for your 24g. I was buying rodi water from my lfs, until I realized I was getting water with close to tds as my tap

Reefing Madness · Feb 26, 2014

I just use one off the E-Bay, been using it for years with no issues, ya gotta change the cartridges just all the rest your going to buy.

tidus10 · Feb 26, 2014

I did the math for myself..to drive to a local fish store and back home was $10.. Buy water was $4.. And it's good practice to do this once a week.. Not to mention walking into the LFS costs me buying something else too... So minimum $14 + a frag * 52 weeks = $728 a year... Or buy my own RODI from bulk reef for $195 shipped and spend $80 a year in maintenance (filters/membrane) is a good trade off for me!!

SloppyJ · Feb 26, 2014

I had the same setup when I first started. I drove and got water. It got to the point where I would neglect my tank because I didn't want to drive to get water.

A RODI unit is THE single best thing you can buy. BRS has some good deals on them. I tee'd it off of the cold inlet to my water heater and ran the waste water over to the emergency drain for the water heater. It works like a charm. I originally had it set up under my kitchen sink and that was just a PITA. Buy one that has a shutoff valve and buy a float valve to connect it to. This will save you many gallons of water on your floor.

tidus10 · Feb 27, 2014

I put a T on my cold water hose at my washing machine, super easy to get to and it drains with my washer too..

I had a 1/4" tee break in shipping, they sent me out another one first class mail. I'll choose bulk reef supply moving forward.

AZDesertRat · Feb 27, 2014

No RO/DI comes close to Spectrapure. They are the only vendor to specialy treat then batch or individually hand test ALL of their RO membranes, use 1 micron or less near absolute rated sediment and carbon block filters on all their systems, custom blend all their own DI resins so you only get the freshest very best for your application and to use only capillary tube flow restrictors. You won't find anything even close at only $130 complete.

http://www.reefcentral.com/forums/showthread.php?t=2173771

http://www.spectrapure.com/

TPetty84 · Feb 28, 2014

Thanks guys!
How often would I be changing filter cartridges with the maintenance on a 24 gal? (Approximately)

AZDesertRat · Feb 28, 2014

With any system you should be changing the sediment and carbon block filters every 6 months to protect the RO membrane. The membrane itself can last 3-10 years or more depending on the quality of your sediment and carbon filters, how often they are changed and the quality of your tap water; Soft water really helps extend membrane life. The DI is entirely dependent again on the quality of your water, the efficiency of your RO membrane, how you make your water and how much water you make. By that I mean frequent small batches of water exhaust DI faster than less frequent, larger batches which you then store in a container for a week or two until gone then make more. It can last say 1000 to 3000 gallons in some cases.

SloppyJ · Feb 28, 2014

I Think you could go longer than 6mo.

AZDesertRat · Feb 28, 2014

Most reputable vendors recommend 6 month intervals for several reasons. One is the sole purpose of the sediment and carbon filters are to protect the RO membrane, if either becomes clogged or fouled ther chances of damaging the membrane rise dramatically. Carbon is made up of billions of tiny microscopic pores where the chlorine is adsorbed, if they are fouled the membrane is toast. Also once the filters get dirty pressure to the membrane drops and your rejection rate or removal efficiency goes down, causing DI replacements to go up and driving the cost of operation up.

If you have low suspended solids, normal to low TDS and softened water it is possible to stretch it out by using pressure gauges before and after the sediment can carbon to monitor plugging and headloss and most importantly a low range chlorine test kit to monitor for chlorine breakthru when the carbon is exhausted. Its easier for most to stick with the 6 month intervals plus you really should disinfect the system each time you change filters to kill any bacteria or viruses inside the housings.

TPetty84 · Mar 2, 2014

Thanks again!

Went to one of the LFS in my area and they offer $1 for 5gals. I'm going to use that for now until I can come up with the extra money to buy my own system. I appreciate all the insightful responses!

AZDesertRat · Mar 2, 2014

The only thing I suggest when purchasing treated water is have the vendor test the TDS or conductivity in your presence before you pay for it. Often the maintanance is not what it should be and you are not getting anything close to 0 TDS water.

TPetty84 · Mar 2, 2014

I'll have to pick up a TDS meter. Whether I have an RO/DI or not it should be a worthwhile investment. Thank you again desertrat for the interest!

TPetty84 · Mar 2, 2014

One more question... What is an "acceptable" range for TDS whether from the lfs or otherwise. Also, do you recommend any brand over another?

AZDesertRat · Mar 2, 2014

Your goal is 0 TDS and any RO/DI worth is cost shoud be capable of that. The difference is in how long or how many gallons of ) TDS water it will produce before DI replacements.

A couple of very good, low cost handheld TDS meters are HM Digitals TDS-3, TDS-4TM and AP-1. You should be able to find and of them for around $25. Be careful though, there are imported knockoffs on ebay that look similar but are not nearly the same quality for around $9. If its less than $20 be wary.

TPetty84 · Mar 2, 2014

I understand 0 is key. But for the convenience of $1 for now, what would you consider acceptable? Also, is it easily contaminated? Like if I put the cap of my container on something not pristine or dust gets into the container will that skew the numbers? Or are dissolved solids just that, dissolved and won't affect my water once contained

AZDesertRat · Mar 3, 2014

RO/DI water is very agressive, it is trying to get back to its natural "dirty" state so attracts anything it can from dirty containers, your hands or the air. Store it in clean food safe plastic containers and covered or capped. If it is not 0 TDS you have no idea what is in it since TDS is not a measurement of anything specific but the best we can do in the hobby so always insist on 0 TDS.

CastAway · Mar 3, 2014

AZDesertRat said:
No RO/DI comes close to Spectrapure.http://www.spectrapure.com/

+1

Lemony Lemons · Mar 3, 2014

AZDesertRat said:
No RO/DI comes close to Spectrapure.
http://www.reefcentral.com/forums/showthread.php?t=2173771

http://www.spectrapure.com/

+1

I am getting mine by UPS today and am super excited! Tons of research, forums, reading and learning about user experience and it was without question the unit to go with.