Reverse Osmosis Units

[penguinpimp1990]

What is using RO water supposed to do? And could a DI unit be used instead of a RO unit?

 

[k.o.d]

Reverse osmosis is the process of forcing tapwater through a membrane that allows only pure water molecules through to the product side, the waste is passed through the other side to drain, most RO units produce 1 gallon of RO water for every 3 - 5 gallons processed, so it is wasteful and something to be thought of when you are on a water meter.
DI water is water that has been passed through an anionic and cationic bed to remove all the impurities by adsorption and chemical bonding

Reverse Osmosis product water and DI water have 0 GH and 0 KH and can then be chemically altered to suit your tank requirements.
RO and DI water cannot be solely used to fill your tank as it is is sterile and will not sustain life, additives have to be added to make it suitable for fishkeeping, but it is nitrate, phosphate, and contaminant free

Dependent on your water conditions DI can be highly expensive, we live in Essex and 1 litre of DI resin lasted for approximately 60 litres before it was shown to be discharged ( resin changes colour )

We have a 100 gallon per day pumped RO and with the reef and the stingray/arowana we wouldnt be without it, but other people quite happily use dechlorinated tapwater with no real adverse effects.

At the end of the day you pays your money and makes your choice

 

[Aquascaper]

The only 'issue' with using tapwater is the nitrates and phosphates that are commonly found in it. The trace elements that are also found in there are not really of any consequence (unless the water board flush the system with cleaning agents - ask Navarre about that ) as long as regular de-chlorinator is used.

One of the main reason why we change the tank water is to reduce the build up of nitrates and phosphates in the tank, using tapwater containing these elements is pointless as its not changing anything - if your tapwater is low in these elements then go for it.

 

[penguinpimp1990]

guess ill have to get a phosphates test kit and see if I can use tap water.

 

[Aquascaper]

Tap water has to have 0ppm of Nitrates and 0ppm of Phosphates to be of any use

 

[penguinpimp1990]

This claims to be a deionization unit, I doubt it works well considering the cheap price, but would it be of any use? DI unit

 

[crazyelece]

Here is the deal with RO and DI. RO does not make totally pure water, however it gets is very close. Usually 95% or so. DI removes everything. The reason most people choose to use both is so the RO removes most of the crap out and then the DI finishes the job. What this does is let the RO do the most work and all you have to pay for is the water and filters. You do not necessarilt lose the waste water unless you choose to. Many people in my area use the waste water for their chiclid tanks. Others use it for watering plants and gardens. After the RO does the heavy work the DI finishes it and doesn't run out as fast. So you don't have to replace the resin as often which keeps the costs down.

You do have to worry about other stuff in tap water such as toxic heavy metals. Copper, lead, mercury, etc. can all be toxic to the fish and corals at much lower levels than affect humans. Also heavy metals don't dissapear and will build up over time. The other negative about tap water is it can change day to day and consistancy is one of the major objectives of the hobby, IMO anything that detracts from consistancy should not be tolerated.

Can you get away with using tap water, yes. But why chance your livestock when the cost of a RO/DI unit is about the same as a couple fish or corral. If it saves those two it has paid for itself. And frankly if you can't afford one, you can't afford this hobby.

 

[steelhealr]

I only have ONE comment to add to this thread. NO tap water. It makes absolutely NO sense to invest hundreds of dollars, hours of sweat and then put tap water in your tank. Why would you want to jeopardize your corals, fish, etc?

Even if you have pretty good tap water, remember, with each water change, dissolved ions will accumulate over time. I would tell any newcomer to hold off on a marine tank until you have the resources to fill your tank with pure water.

Without an RO filter, a DI will shutdown in no time. A reasonable RO/DI filter on Ebay starts at $60-80 dollars, about the cost of your first dead coral on tap water. JMO. SH