RO/DI new to this

Robelli · Dec 14, 2019

So I'm planning on filtering my own water for my first aquarium. Tap water has a TDS of around 350. Seems high but I'm wondering if can I get away with a 4 stage filter or if I should go 5 or 6. I dont know what else is in the water as well.
So your advice will be greatly appreciated.
Thank you!

Opus · Dec 14, 2019

First thing you should do is get a copy of your city's water report, assuming you are not on a well. This will tell you what is in it and if they are using chlorine or chloramines. If they are using chloramines then you will want to get a special carbon filter that removes it. Most people can get by with a 4 stage unit. The good thing about RO units is that if you buy a regular sized unit and not a proprietary one like the Aquatic Life RO Buddie, they are easy to add on extra stages at any time. I'm still running my original 25gpd unit I got back in 1995. I've upgraded the RO membrane to 90gpd and added a DI filter and a second carbon filter.

I would suggest going with one of the sponsors on here such as Spectrapure, Buckeye or BRS so you are sure that you are getting quality filters and RO membranes. With your tap tds of 350 you want to get it as low as you can with the ro membrane or you will be buying a lot of DI resin to get it to zero. My tap runs between 400 to 450 and I have a spectrapure RO membrane and it gets me down to 4 tds before my DI.

MyTankSux · Dec 14, 2019

With tds that high I would add a huge prefilter. It'll save you a lot in the long run on filters and membranes.

PreEvolution™ Dechlorinator System with KDF85/55 Catalytic Carbon Filter

Combination of KDF85 and KDF55 with earth-friendly catalytic carbon filter reduces up to 99% chlorine, sediment, rust, silt, volatile organic compounds (VOCs), mercury, lead and PCBs (organic chlorine). Ensures your Evolution-RO runs more efficiently Less filter changes and maintenance.

www.hydrologicsystems.com

pdxmonkeyboy · Dec 14, 2019

The chlorine vs chloramine is important for sure. You may want to invest in a ro unit that has two membranes, the rejected water from the first membrane goes into the second membrane. That way you are wasting almost 50% less water.

Spectrapure is a good brand.

Saltyreef · Dec 14, 2019

I have a spectrapure max cap standard system. Was fairly cheap and very simple to use. Around $250 on sale. Also its readily upgradeable to their 99% rejection membranes and the high capacity resins.
My TDS is the same as yours. 325 to 360 depending on what water source my city is using.
I dont worry about chloramines as i use the .5 micron carbon block and test my rejection waters total and free chlorine to determine if theres any chlorine or chloramines getting past the carbon. When it does, time for a new carbon block.

So far my system has been rock solid. I bought the DI bypass valve and had them install it before the unit shipped too. Dont bother with a flush kit.

The manual that comes with the system will be all you really need for guidance on when and how often to change filters and ALWAYS use spectrapure filters and resins! Theyre the best in the industry.

AdamB · Dec 14, 2019

Welcome to R2R! Yes that’s high . I agree to in getting a large pre filter as previously stated before .

Opus · Dec 15, 2019

A large pre-filter is not needed. Pre-filters have little to no effect on tds. The sediment filters job is to filter out larger particles before they get to the carbon filter/ro membrane and clog it up. The carbon filters job is to remove chemicals that could harm the RO membrane such as chlorine. Chloramines will not not harm the RO membrane, at least not in the amounts used for water treatment. Chloramines will burn thru your DI quickly and if they get thru will kill your fish/coral.