It behoves me to say before answering Clives thread that i tend to want to see spawning behaviour from my discus, so an RO unit is a necessity for me (i feel) given my tapwaters resemblance to soluble chalk. Buffers and other chemical solutions to softer water just arent viable for me. Certainly if i lived in Cumbria or Wales i would not use an RO unit. Added to this is that, as George pointed out in another thread, 'waste' RO water can be re-used in other applications thus minimising its 'wastefullness'. As to its expense - this is certainly relative. The maintenance of such units certainly arent any more than buying ferts over a year (Id say much less of a year period) and the initial price can be less than £100 for a bare bones unit.
Tap water has an abundance of all sorts of nutrients which all plants, regardless of origin require. We therefore have a much wider margin for error with tap. There are a few species which do better in soft water, Tonina comes to mind immediately.
More accurate to say i would have thought that plants growing in softer more acidic water will be 'naturally selected' to live in this environment and therefore be more suited to this environment in the tank. I shouldnt have used the anthropomorphism of 'happy' really.
If reconstituted correctly it's fine but there is very little room for error
Reconstituting RO isnt some form of complicated art form... its quite simple when following the instructions on most manufacturers products. I have certainly never had an issue with this - even as a beginner to RO.
There is another thread somewhere on the board discussing high nitrates and discus. I believe it was Ivan who is also a discus enthusiast. High nitrates in tap water normally occur in agricultural zones due to runoff from the surrounding farms. I guess I'm not really convinced that 40ppm nitrate levels has any effect on discus growth because they certainly don't have any effect on growth of dwarf chiclids in my experience.
I have to disagree with this with all due respect. Any look on any of the discus fora out there and there is a wealth of opinion from breeders about how high nitrate levels are ONE OF the major reasons for stunted growth. I have also bred discus in my tap water and in reconstituted RO and the survival rate is better in the latter. This is my personal experience.
Different species also have differing tolerances and so different rules apply i would have thought. Breeding convicts is a far easier task than breeding discus and i have done both.
Effects on growth can be found more in NH4, nitrite, organic waste, foul water, high TDS and poor feeding.
Certainly all these are undesirable...
If one is trying to grow out discus fry it might be better to use a non planted tank if max growth is the goal certainly, but it seems to me that would be more because of practical concerns such as cleaning, feeding etc. than nitrates.
Certainly an ideal and i dont try to grow out any discus from fry stage in a planted tank. Though having said this i dont see why it CANT be done. I would imagine survival rates would be lower.
It also seems to me that one of the other benefits of RO is that it filters out viruses and bacteria as well as toxins so the risk of pathogens to the fish is minimized.
Absolutely. Better imo to get the rubbish out and then build the water back up than risk £100's of stock fish?
In any case plants can be grown in a wide variety of conditions but the optimum conditions for maximum growth are without a doubt water with very high concentrations of NPK and high but non-toxic levels of minerals and metals, which, again, is true for all but the most specialized type of plant.
...and this is easily done following EI in reconstituted RO water. Especially when using the powdered form of ferts.
My point really is that I personally prefer to get H2O to a position of purity that cant be achieved from tap water and then work to a usable ‘base’ water from there which will be typically low in Nitrate, KH and GH. It will also be free of pesticides, other toxins and pathogens. This is just my method of doing it and for the sake of my expensive fish stocks sake I will continue to do so. The issue being can plants also survive in this water – I believe they can with just as much careful maintenance as most of the forum members here display toward their planted tanks. If you go into anything without researching properly and consulting sites like this then you invite a certain level of risk.
Yes i guess as a beginner you can de-risk under-dosing ferts in planted tanks by using tapwater but not imo when keeping discus. I personally feel the trade off in terms potentially stressing my discus isnt worth it. There is no substitute for researching your topic i would say.