RO SYSTEMS

[Adamas]

Is an RO System good for aquariums or do you need to have RO/DI at all cost ?

 

[Anonymous]

I would say it's very good for aquariums. I believe an RO will bring the TDS down to 5-10ppm, and a DI will take it all the way down to zero ppm. Do you need to have DI? No, imo.

 

[Anonymous]

>....Do you need to have DI? No, imo.

Agree. DI is needed only if your tap water is so bad that RO is not doing enough.

 

[aquamarine]

I agree that some type of filtration is highly necessary to ensure a clean slatewhen doing top off or mixing, though I also have to say that a DI is a fairly necessary addition to the filtration process because you dont know what exactly that left over 10ppm consists of and typicaly the things the membrane does not take out just happen to be things that are harmful to your tank. So IMO for what its worth, yes use a DI

Bryan Crenshaw

 

[Anonymous]

RO will actually cut about 90% of the TDS from your tap water.

My tap is horrible.

350 TDS
35 after the RO
4 after the first DI adn 0 after the second DI. I do go through DI very very fast.
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[Adamas]

Guys how can I check how horrible is my tap water ?

 

[Anonymous]

Guys how can I check how horrible is my tap water ?

Your local City government should have a public works department that can give you that data, if they don't have the data and you don't want the expense of buying the test equipment to do it yourself perhaps a local fish store might do that for you.

But I would try the City first.

 

[Anonymous]

You can buy a TDS meter for about 25 bucks. I think Hanna is one of the more popular brands.

They are handy to have around. You test your water and when the TDS is up you know its time to replace your filters.

I use RO/DI. I like a low TDS. Zero sounds good.

Louey

 

[Anonymous]

Adams your location says Malta, is that as in the Maltese Islands?

 

[Fastmarc]

Hmm...
It's not just about TDS.
There are a number of compounds that make it through a RO membrane that we as reefers should be concerned about, but the DI resin takes care of. These include ammonia (NH3), hydrogen sulfide (H2S, especially a concern with well water), silicate and CO2.

 

[sediener]

Hmm...
It's not just about TDS.
There are a number of compounds that make it through a RO membrane that we as reefers should be concerned about, but the DI resin takes care of. These include ammonia (NH3), hydrogen sulfide (H2S, especially a concern with well water), silicate and CO2.

ammonia? If my RO is why i have algae problems, I will shoot myself. My TDS is 0-2 coming out and I always figured I was safe. Time to test the RO.

- steve

 

[sediener]

Son of a b****! someone get me a gun... or a DI column.

Coming out of the RO with a TDS of 2 ppm

NH3- slightly colored, not 0 but not to the kit's next level.
NO2 - .5

Anyone know where to get a good 2 column re-chargeable addon DI?

-steve

 

[aquamarine]

Sorry to take up so much room here but here is a list of rejection rates achieved through a standard ro membrane.Hope this helps a little
Bryan

Aluminum 97-98%

Calcium 96-98%

Ferrocyanide 98-99%

Nitrate 93-96%

Selenium 97%

Ammonium 85-95%

Chloride 94-95%

Flouride 94-96%

Phosphate 99+%

Silica 85-90%

Arsenic 94-96%

Chromate 90-98%

Iron 98-99%

Polyphosphate 98-99%

Silicate 95-97%

Bacteria 99+%

Chromium 96-98%

Lead 96-98%

Potassium 92%

Silver 95-97%

Bicarbonate 95-96%

Copper 97-99%

Magnesium 96-98%

Radioactivity 95-98%

Sodium 92-98%

Cadmium 96-98%

Cyanide 90-95%

Maganese 96-98%

Radium 97%

Sulphate 99+%

Sulphite 96-98%

TDS 95-99%

Zinc 98-99%

Virus 99+%

Insecticides 97%

 

[Fastmarc]

If you are using tap water and it contains chloramine, that could be the source of your ammonia.
The activated carbon in you RO effectively breaks down chloramine and produces ammonia, chloride, and nitrogen gas. Of course ammonia is the one that would most concerns us, but a DI would effectively remove it.
IMO, a DI is necessary.