Are Ro Units Essential?

[shawn-b]

I've been using an RO unit for a couple of years now as I keep discus. I use a ratio of about 2:1 of RO mixed with tap for my water changes and have found that my water remains nice and stable and the fish seem fine with this.

It's time to replace the RO membrane as the TDS is starting to climb and the time it takes to filter the water is reduced from about 4-5 hours for 25l to about 90 minutes to do the same and then flood the kitchen floor!

MY water from the tap parameters are:

pH - 7.6
Nitrate - 5 mg/L
Ammonia - 0
Nitrite - 0
Phosphate - 0.25 mg/L
kH - 50ppm
gH - 120ppm
Iron - 0
Iron (chelated) 0
Calcium - 40 mg/L

All test are carried out using the Hagen Nutrafin master test kit (liquid drops and colour change charts so any dodgy readings are probably down to my dodgy eyes comparing the colours )

Which brings me onto my question

I've read a bit about HMA and CBR units but not sure how they work in comparison to an RO unit, other than they don't waste water to the extent of an RO unit, therefore was wondering if one of these units would be suitable for the needs of my fish or am I better staying with the tried and tested RO units?

Any advice before I try and persuade my wife to let me spend more money on my fish would greatly appreciated.

 

[thegnu]

in my case i think my ro unit IS essential because my tap water has a nitrate reading of 40PPM. i keep discus, apistogramma's and rams. they wouldn't last long in a tank with that high a nitrate before they have even had time to push it even higher. if you could bring your pH down to just under 7pH by using peat, i think you could do without your ro unit

edit; i've just seen the time it takes for your ro unit to produse 25L of water. mine takes EIGHT HOURS to filter 20L

 

[shawn-b]

edit; i've just seen the time it takes for your ro unit to produse 25L of water. mine takes EIGHT HOURS to filter 20L

Hence my belief that it's now knackered! Coupled with the rise in TDS that is...