RODI Filtration Help!!!

[Albertan22]

Thanks for the clarification. Even still. My alk has never skyrocketed to 20dkh in a fresh mixed batch of salt water using tap water....

My tap water is very hard and has a really high alkalinity naturally without anything mixed in it. I’ve never mixed salt into it but I could easily see IO which mixes naturally around 9dkh jumping the alk up to around 20.

 

[Albertan22]

It sounds like something is off with your membrane. Either it isn’t seated properly, it’s not plumbed right, or it’s defective.

 

[bblumberg]

Can you please post a photo from the top down showing what lines are connected to where on the RO unit? This will help us to troubleshoot your problem.

 

[Marco S]

How do I run a 6 stage? And I just changed this a few days ago and it turned colors immediately. I've only made five gallons of water. Everything I've purchased was from marine depot. Including their filters.

A six stage just means you have two more stages than a 4. You can either order one already configured or just add two more stages to your unit. Here is a pic of my setup just to give you an idea of what you probably should have...

I also have the gauge to check pressure, a back-flush system, a TDS Meter and a pump since my water pressure was pretty low. One more step I took was to include a pre-filter on the water supply connection before it even hit my RODI system...

I also have a splitter in the line before the DI because I use this for regular drinking water as well.

Hopefully that helps some.

 

[bblumberg]

You do not need a 6 stage RO unit just because you have high tds. The RO membrane does all the work on lowering tds. The prefilters are just there to protect the RO membrane. If you are trying to lower a certain chemical such as chloramines or a metal then 2 carbon filters may be warranted, with one of them specializing in what you are trying to get rid of. If your RO membrane is old or if your carbon filter was old and it wasn't taking out the chlorine (assuming you have it in your source water), the chlorine will eat holes in the RO membrane. Water pressure could be an issue but doubt it would be giving you that kind of tds reading. Were you getting the 300+ tds reading before you changed the prefilters and DI?

If your RO membrane is fairly new, did you install it yourself. As stated it could be installed wrong.

Umm, not completely. Carbon block filters do indeed protect the RO membrane from chloramine, but they also serve a very important role in removing organic contaminants in the feed water. Carbon block filters can reduce, but do not eliminate minerals such as lead, asbestos, metals, and various other minerals. RO primarily removes these small inorganic molecules such as metal ions, carbonates, etc. Then the DI resin removes any charged materials remaining. I can see little reason for only having 1 carbon block prefilter and 1 DI resin cartridge. I have 2 different porosities of carbon block prefilters in mine and actually use 3 DI cartridges.

 

[Slushi]

A six stage just means you have two more stages than a 4. You can either order one already configured or just add two more stages to your unit. Here is a pic of my setup just to give you an idea of what you probably should have...

I also have the gauge to check pressure, a back-flush system, a TDS Meter and a pump since my water pressure was pretty low. One more step I took was to include a pre-filter on the water supply connection before it even hit my RODI system...

I also have a splitter in the line before the DI because I use this for regular drinking water as well.

Hopefully that helps some.

This is great help, thank you. Can you tell me about the pre-filter? Also, are they interchangeable? Since mine is from marine depot, can I buy the two stage from brs?

 

[oceanslide]

I would check out some YouTube videos and diagrams to make sure everything is setup in the correct order because the filters should not exhaust that quickly.

 

[Marco S]

This is great help, thank you. Can you tell me about the pre-filter? Also, are they interchangeable? Since mine is from marine depot, can I buy the two stage from brs?

Yes they will work together as long as you're using the same size tubing. BRS units all use 1/4" tubing, but not sure what Marine Depot units use. If it is different you would just need to buy an adapter that would connect 1/4" tube to 3/8" or 1/2" or whatever the size tubing you have. The pre-filter and any adapter or part you need is available at BRS and in the rare instance that a part is out of stock I have used Fresh Water Systems.com for parts or just run down to the Home Depot to get more 1/4" tubing.

Edit: I should add that if you get a 2 or 3 stage DI unit, you will probably want to use the chamber you currently have DI in for another carbon filter instead of DI.

 

[Saltyreef]

My tap water is very hard and has a really high alkalinity naturally without anything mixed in it. I’ve never mixed salt into it but I could easily see IO which mixes naturally around 9dkh jumping the alk up to around 20.

Precisely why i asked about testing tap.

And youre absolutely right....i agree

 

[Spieg]

Man that is some bad source water you have (do you live in Flint Michigan? LOL). My gut says you have something setup wrong. When you replaced your filters, are you sure you got everything put back in the same place they came from? As someone already stated, it would be a good idea to remove the RO membrane and re-seat it (if a seal isn't set right, and water finds a path that doesn't require going through the membrane, it will take it). For comparison, I usually get between 2-5 TDS coming out of my membrane before it gets to the DI filters.

90% of the RODI systems out there for hobbyists use the same 1/4" tubing so they're very interchangeable.

 

[Opus]

Umm, not completely. Carbon block filters do indeed protect the RO membrane from chloramine, but they also serve a very important role in removing organic contaminants in the feed water. Carbon block filters can reduce, but do not eliminate minerals such as lead, asbestos, metals, and various other minerals. RO primarily removes these small inorganic molecules such as metal ions, carbonates, etc. Then the DI resin removes any charged materials remaining. I can see little reason for only having 1 carbon block prefilter and 1 DI resin cartridge. I have 2 different porosities of carbon block prefilters in mine and actually use 3 DI cartridges.

You might want to reread what I said. You basically repeated me with just more detail, other than the fact 2 carbon filters isn't warranted in many cases. Just because you have 2 of them doesn't mean the OP needs them.

@Slushi, check your city's/water district's website. They are required to do water analysis all the time and most post the current published numbers in pdf format for you to download. Also, all these RO systems sold by BRS, MD and a host of others are all the standard 10" canisters, the only difference is the filters they use inside. Unless you buy a portable unit or the larger 20" model, you can just buy more canisters and filters. Some places will sell a kit to go from a 4 stage to 5 or 6 stage. My RO unit is over 25 years old. I've added to it and changed filter brands several times. Mine started out as a Kent Marine 20 gpd unit, which at the time was more $$$ than what you can buy a 75 gal unit today and no one had DI back then. Now mine does 90 gpd using a spectrapure 99% rejection rate ro membrane. My tap tds is over 400 and it is 3 or 4 tds before the DI now.