RO v's Tap Water

[Jason Blake]

Hi,

I would just like to know all the pro's and con's concerning RO and Tap water? I have always used Tap water before however, I have branched out in the Marine world where RO water is almost mandatory. Therefore I have purchased an RO unit. 1p a litre (including the waste water) v's 75p for 5 litres was a little bit of a no brainer!

I hope to start up a new freshwater plant tank sometime soon. So I am just wondering which is best and which type of water to use?

RO water from what I can understand, you have far greater control over the parameters of the water. Will also provide opportunity to keep more demanding live stock. However producing RO water is extremely wasteful, even more so as I live in a "Hard to Very Hard" water area. 4 litres waste to every 1 litre of RO water. Membranes will need to be replaced more frequently with my type of water.

Tap water is less wasteful, cheaper to use and the water naturally contains a lot of useful elements but can also contain to many other not so desirable elements. Also keeping more demanding speices maybe more troublesome.

Thats my understanding thus far. Is that correct? If there anything else I need to consider before deciding which type of water to use?

Thanks.

 

[Sacha]

Sounds like you need a diaphragm pump for your RO unit. My tap water is the hardest in England apparently. And with a diaphragm pump to put 110 PSI Through the unit, I get 2 parts RO to 1 part waste.

Before I had the pump and the unit pressure was like 35-40 PSI, the ratio was about 3:1 waste:RO like you say.

Your membranes will last longer if they have adequate pressure through them and you ensure to flush the membranes after each use.

 

[GlassWalker]

Personally I think the biggest consideration will be the type of livestock you keep. Use it if you know why you need it. If you want to keep acidic, soft water fish, then hard tap water wont be the best for them. I currently run one very soft freshwater tank (KH1, GH6) primarily for shrimp. My tap water is nearer KH10 GH20 so not even close.

Also consider for marines it is standard procedure to run DI resin after RO to eliminate any nitrates and phosphates getting through. Freshwater planted tank theory doesn't seem applicable to marines there! But if it will save you some cost, you could bypass the DI when making RO for freshwater as residual levels of anything are not so important there.

 

[ceg4048]

I hope to start up a new freshwater plant tank sometime soon. So I am just wondering which is best and which type of water to use?

I agree with Glasswalker. All but the most specialized of plants don't really care what kind of water they are in as long as that water is high in nutrients, high in CO2 and importantly, as long as that water is kept clean.

Cheers,

 

[Jose]

I would only consider RO water for certain fish and not so much for plants. Unless you were to keep Discus, German Blue Rams or such fish I wouldnt worry about RO.

 

[tam]

You could always use RO to dilute your tapwater. That will reduce your hardness without being as expensive/wasteful as going pure RO. It's handy for top ups too.