• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

RO water


17 Nov 2007
Does anyone out there still use RO water. There appears to be very little mention of it on any of the forums. I was wondering what products people use to re-build the ro water for their tanks. I currently use SERA mineral salt for trace elemnts and KH increase but would be interested to hear what other people are using.
Yep, I use RO water. I just add a bit of tap water to bring GH up to about 5. I also add a bit of magnesium as my tap's GH is all calcium. KH I try to keep low at about 2 to 3.

I use RO too. I have Seachem Equilibrium to re-mineralise it but had a few issues with stunting and have now got some more Kent RO right and the problem's gone!
i just use my r/o straight over peat in storage butt then , neat in tank for apisto's
or mixed with tap for plants

assuming 95 efficency of r/o , and my quite hard london tap there is likely still some things left
my fish seemed to liek it then that is what evolution had adapted them to

I use RO water, with TMC tropical remineral added. My tapwater is loaded with all sorts of chemicals. When I used tapwater I had all sorts of problems with algae, now using RO water its not nearly so bad.
A belated Happy New Year to all UKAPS members.

As users of RO I assume all you guys have your own RO producing units. I'm looking to buy one in the near future and would be grateful for any tips/advice on installation/operation please?

I dont use RO, i used to.. and now my plants grow better in the tap water. Plus, personally, I condiser it an unnecessary environmental strain with huge wastage. I understand the need to use it in certain tanks with certain breeds of fish, but for a normal planted tank, cant see the need for it unless you live in the States and there horrid.
Terry said:
A belated Happy New Year to all UKAPS members.

As users of RO I assume all you guys have your own RO producing units. I'm looking to buy one in the near future and would be grateful for any tips/advice on installation/operation please?


I have a 50 gallons per day unit from RO Man and would definitely recommend them.

My product water feeds into a 100 litre slimline water butt and that is fitted with an automatic shut off and, at the bottom, a full flow tap with a ball valve rather than a standard tap.
When I need water I simply open the tap and fill the containers quickly rather than leaving them for hours to produce the water!
All the waste water is used by letting it flow into my koi pond where the slightly higher hardness and nutirents don't matter at all. Therefore my RO wastes nothing! (In theory! ;) )
You definitely want to think about using the 'waste' water somehow (either hard water tanks, ponds or watering plants that aren't fussy), though all the RO units in Britain must waste less in a year than the water companies lose in a day through leaks...

Personally I wouldn't be without one as it allows me to keep and breed a wide range of wild, F1 and sensitive species. I'm experimenting with tap water in my tanks at school and everything seems ok so far, except the duckweed has really taken off in one tank and the Mayaca growth has slowed in the other (though there are a million and one reasons why those changes may have happened, so I'm not at all saying the tap water has definitely caused them) but I doubt the pair of wild angels will breed successfully in it! :lol:
Does anybody know the conductivity of the product?

..of the product water? Very low from memory - around 20-40 ms (cant do that funny u shaped symbol - microsiemens) on my RO unit. I have very hard input water though so this could be lower on other RO units, also polishing DI units would get this lower i imagine?

When i reconstituted it with minerals i would aim to get up to 200-300 ms.
Hah! Na Na Na Na Na. I can get freebie RO at 0.02 microSiemens/cm. The only problem is, I don`t need it. :arghh:

hmmm...ok. Like i said depends on many factors - hardness of water going in, the temperature of that water, mains pressure etc etc. I would be surprised if an RO unit without a DI unit could produce that low a reading and as i remember my TDS/conductivity unit didnt go down to tenths of a microsiemens? That was a Hanna hand held job - widely held to be one of the best hand held units out there, outside of a lab anyway.

You would be welcome to send me the unit and i could prove it one way or the other with London tapwater at barely 1 bar of mains pressure!?
Sorry, Steve! I was being flippant. :D

I am referring to the water treatment plant at the power staion where I work.

stevet said:
Free RO water - great!?

Just take a few water carriers to work....

I have very soft tap water, so the only use I have for it is making my own 4dKH solution.

Hmm after reading all these thread about RO water I start wondering if there is any point in using remineralising salt? If you look at the content of all these water conditioner, they only add potassium, calcium, magnesium, and trace element back in the water. Surely if you are dosing with EI, there is no need to add those element back in the water as there is plenty in the fertiliser. Am I wrong in saying this?