rodi replacement parts

I bought a rodi unit from craigslist and I've lost the paperwork. I'm guessing it is time to replace some filters/membranes/etc, but I'm not sure if I can choose anything or if I need to buy parts for my model only. I've attached a pic of the unit.

 

Most units (including yours from the look of it) have a standard size for the cartridges. Bulk reef supply should be able to hook you up.

 

Any RO or RO/DI vendor has what you need and in the preferred micron ranges.
My first choice is SpectraPure Water Purification Products but also recommend www.buckeyefieldsupply.com , FL Aquarium Water Filters Reverse Osmosis Booster Pump GFO Nitrate DI Carbon or Melevsreef.com - Welcome! . You will probably want a 1.0 or better yet a 0.5 micron prefilter and a 0.5 micron 20,000 gallon chlorine guzzzler type carbon block. If you go with Spectrapure you would want a refill kit of their SilicaBuster DI resin which they custom blend for reef use.

Don't go any larger than 1 micron on the filters since their job is to protect the expensive RO membrane which in turn protects the DI resin. Going larger or going cheap fouls or plugs the membrane quicker leading to failure and increased DI usage.

While you have it apart for filter replacements disinfect the system. You can find my method on 3Reef if you do a quick search for RO/DI disinfection.

 

you dont have many filters on that unit, probly going to be like 5 micron sediment, 1 micron carbon, RO membrane, DI resin..

I am adding to mine right now, it wil be 10 micron sediment, 5 micron carbon, to a canister of GAC for chloramines, then a 1 micron carbon, RO membrane, to tank, then DI. you can buy brackets and canisters and and just chain it together. Ive also seen a 1 micron carbon placed after the tank to the DI as well. may do that as well.

I would add another bracket with some more canisters/filters and replace the filters you have. BRS and Air water ice got what you need.

 

Always make sure your prefilter is close to the same micron range as your carbon block so you don't plug the billions of tiny microscopic pores in the carbon and render it useless. If you use a 1 micron carbon use a 1 micron prefilter, a 0.5 carbon a 0.5 prefilter etc.

Chloramine carbons are a waste of money. Stick with the Matrikx +1 0.5 or 0.6 micron carbon block and you have more than you will ever need. Catalytic carbons are for chloramines way in excess of the 4 mg/L allowed in drinking water. If chloramines are in fact an issue then you need to beef up your DI, not your carbon. The carbon easily removes the chlorine portion, its the ammonia that is the greatest concern andwhere the better DI resin comes in to play. RO is not particularly effective at all forms of ammonia so a good DI is a must.

Check out Spectrapures absolute rated prefilters, mush more effective than the normal nominal rated filter (there is a difference) and their custom blended SilicaBuste rDI resin which is specifically blended to be the best for ammonia, nitrates, silicates and phosphates.

 

Wow...thanks everyone. That is tons of info. I might be over my head. Is there a specific way to tell when each piece needs a change? I have no idea how much water was put through the system before I got it.

I was told when I bought it that it was a 75 GPD system, but I only use it for a 12 gallon tank. I know the safest thing to do is replace it all, but I'll need to know in the future if there is a good way to measure use or a good way to measure whether they clog early, etc.

 

First off you need a TDS meter to determine the condition of the RO membrane and DI resin. You take your tap water TDS, the RO only TDS then the RO/DI or final TDS. The RO only TDS should be about 96-98% less than the tap water TDS if the membrane is operating correctly, less if its getting worn out. The RO/DI should be 0 TDS or very close to it. A handheld TDS meter like the HM Digital TDS-3 or TDS-4 with the temperature option are good choice in the $20-$25 range. Inline meters have limitations, one of which is it is dedicated to two points and thats it so no testing the tap water which is important. With the handheld you can test your water storage, tap water, RO only, RO/DI, the neighbors, the LFS, a vending machine etc.
Another is they are not temperature compensated so not as accurate. They can be off as much as 2% for every degree C difference between your water temp and air temp whch are rarely the same.

The prefilter and carbon block get changed every 6 months like clockwork and have no effect on TDS so cannot be tested with a meter. They are there to protect the expensive RO membrane so this needs to be kept up with. Always disinfect the system when changing filters follolwing the directions I have posted many times if you do a search.

 

Yep...thanks again. This is great info. I have battled tap water issues for too long. I started using this unit about 6 months ago so I am probably long overdue for a change. I don't use it much for the 12 gallon tank, but I don't know how old they were before me.

Just bought a TDS meter from ebay. I'll see what the water is like when it arrives, but I'll also order the sediment and carbon filters in the mean time.

I think some of this info should be in a sticky at the top of this category.

 

Just a suggestion, as it wasn't mentioned earlier, you may need to replace your DI resin as well, and your canister doesn't have enough resin in it as it is.

After looking at the above mentioned suppliers, noticed they all have clear housings, which in most cases is not a good idea. This is because the light getting into the housings will create a build-up of algae within the canisters. It is recommended to have a solid color housing.

I also noticed that the systems are usually a 3, 4 or 5 stage, whereas Aquasafe Systems offers a 7 stage for roughly the same price with 3 DI stages.

 

Only if you're gonna leave it out in direct sunlight. I know mine, while it has clear canisters, is under the sink. On top of that, it gets disinfected every 6 months when I change the carbon and prefilter.