# Getting an RO unit



## Aeropars (20 Jul 2007)

I've decided to get an RO unit from RO-Man.com and all the associated bits. Looking at a 75 gallon per day jobbie without a DI unit.

I'm going to be using around 25% tap water to 75% RO water to give me a KH of roughly 4.

By doing this, will I need to add any minerals back into the water? Or will the tap water provide sufficient quantity of minerals for a healthy tank?

I measured a KH of 15 out the tap last night and have seachem onyx sand which buffers slightly as well so I calculate 3.75.


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## JamesC (20 Jul 2007)

Depends on your tap water what you need to add back if anything. I add a bit of magnesium only because my GH is nearly all calcium. If you're dosing EI then the rest of the required nutrients are supplied that way.

James


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## Aeropars (20 Jul 2007)

Well, it will be PPS pro for the moment but using all the same stuff that EI uses.


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## JamesC (20 Jul 2007)

I looked at that PPS-Pro but it was basically PMDD with a bit of PO4 added in to the equation. Not quite sure why it's been claimed as a new dosing method when people have been doing it for years, but there you go.

I have taken the PMDD formlulation and added some PO4 in and have been dosing this for three weeks now. I've used a bit more PO4 than what PPS-Pro uses because of all the GSA problems it seems to have. Results have been very good so far with this leaner dosing method with more compact growth and no algae.  I've detailed what I'm doing on my website if you're interested.

James


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## Matt Holbrook-Bull (20 Jul 2007)

Be careful if your on a water meter, the wastage from an RO unit is mindblowing.. and I mean, mindblowing


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## Fred Dulley (22 Jul 2007)

The waste water is full of minerals and some RO units remove the chlorine.Sounds like good water to me.  Why not use the waste water instead of  tap? 25% waste, 75%RO.


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## Matt Holbrook-Bull (22 Jul 2007)

absolutely Fred, RO units are all very well, but the environmental issues surrounding them tend to muddy the water a bit, no pun intended.  I just use my tap water, and its fine, not all of us are able to do that I realise. 

Taking everything out of the water for a planted tank isnt a good idea anyway, you have to remember its a totally closed system your creating, and therefor relies on you for EVERYTHING it needs.  

using the wastage water from the RO unit could be a very interesting option that maybe hasnt been thought of before.. if you have marine tanks then it might be the perfect combo, or if you know anyone with marine tanks who would benefit from the full RO water, why not go halves?  Id be really interested to see how that worked out.


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