RO/DI unit

[Creetin]

ok i guess its my turn now, cant run away from diatoms, they keep coming back! mi questions:

1. issit a guarantee that getting the above will eliminate phosphates n hence diatom growth?

2. saw some fellow reefers mentioning getting one for the family? issit cheaper like tat - ie. one tat can dispense water like water cooler...

3. how does the normal fishy RO unit work. do they connect direct to the tank via tubes like a canister? or sthg like a bucket tat u use to perform water changes?

4. any good brands?

Thanks!

[ep4546]

i have a DI for sale wonder if you are interested

[Creetin]

hmmm wats the diff btw DI and RO? heard that RO is better den DI? and also, how much u selling urs? how does it work......?

me veri the green in this area. tot the unit was like a chiller running on electricity! haha....now den i know (tks wedgee) tat its sthg like a filter tat connects to the tap?

[Tanzy]

RO stands for Reverse Osmosis. This is a process where tap water is forced through a filter membrance under pressure and the unwanted stuff are left behind. It is about 98% pure.

DI stands for De-ionization. The water after processed through RO membrane is passed through a column containing DI resins that 'absorb' all impurities left. This is close to 100% pure water.

Of course the process is more complicated than that but this is the main theory behind RO/DI.

[Creetin]

so which is better? RO or DI?

btw, how do they work? issit like a filter connecting to ur tap? ani elect needed?

[Tanzy]

Hmmm, DI being near 100% will be better I assume. Usually they are used in combination. If tapwater is passed straight through DI column, the resins will get exhausted very fast. Running both RO/DI will keep cost down. The unit is usually plumbed directed to a tap using an adapter. Sometimes, if the pressure is insufficient for RO to work, an additional pump must be used.

[Creetin]

hmmm i suppose RO is cheaper den DI rite? wat are prices like? wedgee said he found one RO unit at keong seong sellin for $200+.... ani good brands?

issit GURANTEED no diatoms?

[Morgan]

issit GURANTEED no diatoms?

NO

[Creetin]

but i supposed it helps? hence the good publicity......

[Morgan]

Have you consider the amount of water you are going to waste for every 1L of RO/DI water you get?

[Creetin]

no but now u said it i recall that the ratio is about 1 to 4?

its a trade off i guess.... but also may look into other methods of phosphate removal?

[wedgee]

Hmm all dat said, u might just as well consider getting an RO good for drinking for yr family...I'm using one right now, and it seems more worthwhile cause u can use it for reefing and to protect yr kidneys and stuff! But they dont come cheap, esp U.S-made ones (better than those in shopping centres)

Btw, a good RO removes mostly 'solid' compounds, including heavy metals - Lead, Mercury, Cysts, particulates courtesy of our old pipes - all these stuff can be removed, even chlorine and chloramine!!!

DI on the other hand, removes those dissolved chemicals and minerals that RO cant get rid of, or are not designed to get rid of, like phosphate and nitrates and stuff!!!

Dat is why using a DI only will practically destroy the resin quickly, and it is more common to use RO before DI...

Creetin, other methods work only up to a certain degree (like sponges and filter resins in the tank), so the best way is to remove it immediately from the source water...

Oh yah, btw, RO at 200+++++ while DI at only 75 bucks!!!

Anyone pls correct me if i wrong...

[BlueTerror]

any links/websites to find out more about these DI/RO units and their prices?

[Tanzy]

You can try Spectra Pure. My RO/DI is from them, ordered straight from their online store. I don't know if it is the cheapest but it is quite reasonable.

I don't use RO/DI for my reef. Tap water works well for me. Morgan is right about the waste water, but I use the waste water for watering plants.

RO/DI will only get rid of diatoms if the source of your diatom problems is due to silicates in the tapwater.

[robe]

RO is typically much cheaper in the long run if u use a lot of water. With care Ro membranes lasts 2 to 3 years. If u can use the waste water for laundry or flushing toilets then it does not necessarily results in waste.

I did not have any diatom blooms since using RO water for top-up and changes.

I also used DI before but found them expensive, the DI resins last only 200-300 litres before it is exhausted. At $50 per tube it burns a hole in your pocket.

Anyway 98% removal of contaminants is good enough.