DIY Water purification with DI, skip the RO Membrane - Thoughts?

[LogFish]

Hey Guys,

Being in Malaysia, it sometimes sucks for the price of thing's. Price of an RO/DI unit is gonna kill me for sure on my budget, especially if i go with already assembled unit such as crystal / D-D.

Was looking at purchasing a unit from direct manufacturer, i found one, but without DI stage. Price is acceptable, but by the time i add DI stage, it blows as well.

So, this is what I'm having in plan, want some input and thoughts from the more experienced.

My direct Tap water is registering about 50 TDS.

Am gonna buy a 4 stage empty canister, which is pretty darn cheap. and add the below inserts.

1st stage, 5 micron spun fiber sediment filter
2nd stage, Granular Activated loose carbon
3rd stage, Activated Carbon Block Prefilter
4th stage, BRS insert cartridge and BRS DI Resin

By not using RO membrane, what are the possible contaminant I'm gonna let pass in my system?

Any possible issues you guy's foresee here?

- I'm gonna run RowaPhos in TLF 150 reactor
- I'll be running Matrix Carbon in a mesh bag before the return section of the sump.
- I'll be also keeping a fuge (Chaeto) about 10% volume of my DT
- I'll be using Polyp Lab Bio Sphere as nitrate absorbent in a mesh bag at the overflow section.

Am i safe with this setup?

I will conduct phosphate, nitrate and ammonia test on my tap water tonight.

 

[ravi197699]

As long as your output reading is 0 or near 0 then you should be fine but again this is my take, I am sure other members will give your their input as well....

 

[jedimasterben]

The prefilters do not alter the TDS of the system, they are there only to protect the RO membrane. With 50 TDS going into your DI resin, you'd be lucky to get 50 gallons of water out of it before exhaustion.

 

[hllywd]

I agree, I think you'll burn through DI resin pretty fast.

You say you found a manufacturer direct RO unit without DI that is reasonable but adding the DI isn't. Then you're adding a BRS DI canister to your proposed system and it's affordable? What am I missing?

IMO, at 50 TDS I would rather have a good RO system without the DI if I had to make the choice.

 

[Soolaimon]

IMO, at 50 TDS I would rather have a good RO system without the DI if I had to make the choice.

+1

An RO membrane would get this to around 2-3 TDS. Then you could save a lot more in the long run by not burning through DI resin. You could always add the DI step in the future.

 

[ReeferAl]

Here's another option. 50 ppm isn't much in tap water. Get the water tested and see what makes up the tds. If nitrate and phosphate are low, just use tap water. You would still want to run it through activated carbon to remove chlorine and most chemical pollutants. You could also use gfo as it will remove phosphate, silicate and some other contaminants like arsenic. Many people with high quality tapwater do fine without RO/DI.
BTW, do you not have access to natural sea water? I'd use that if I were close to the ocean in an unpoluted area.

As an aside, I always use RO/DI because I do NOT have high quality tapwater. Tds runs a few hundred and nitrates are high as well as trace arsenic.

Allen

 

[LogFish]

Ok guys, will heed the advice given, would go with an ro system the least.

I would also test the tap water to check what's my tates phos running at.

In the mean time I found a di sealed cartridge for 70% cheaper than BRS cartridge and di resin, just not sure of the quality.

My proposed system turned out cheaper in cost as I forego the Dow filmtec membrane and booster pump.

I will be going to the manufacturer today, will check out if a 3 stage ro turn out cheaper for my needs, then I could add the di unit without blowing budget, at worse case, would go with ro only.

For a LPS and ZOA dominant tank with few starter SPS like bird nest and Monti, would the 2 to 3 tds pose any issue's? By having gfo, carbon, chaeto and grates absorbent, would I face algae issues down the road with 2 to 3 tds?

Thanks for clearing my doubt's...

 

[hllywd]

Depends what's breaking through. I'm on a pretty decent municipal system and run right around 120 TDS. With all fresh filters RO takes that to 0. My DI lasts a long time. You may be surprised how well a 3 stage system performs with only 50 TDS in. It is however possible you could have problems.

 

[disc1]

And keep in mind that DI resin won't filter out any neutral organic compounds, only things that have charges.

 

[Buckeye Hydro]

Why in the world would you import products all the way from the US?