Tourney said:
Actually after making some enquiries, a friend of mine has got a reverse osmosis unit for sale, so i will be trying that. Basically i am trying to make the Co2 input more effective for my plants. I am still learning about the relationship between KH, Ph, and Co2, so please excuse any ideas or thought of mine that are incorrect, but I'm just trying to get a clearer idea about it all really.
If i use the RO unit, should i use 100% RO water or a 50-50 mix with dechlorinated tap water? And i assume with the RO water i do not need to use a product like Aquasafe, but obviously in the tap water i still do? :?
Hi Tourney,
Nothing to excuse, really. That's how we all learned - by asking and reading. It all a bit complicated - chemistry, biology, fluid dynamics, construction...it's amazing!
You may want to check this post in the cookbook section to get a better handle on CO2 and it's measurement in the tank:
http://www.ukaps.org/forum/viewtopic.php?t=467
Now, as regards the effectiveness of CO2, as you'll read in that post in the link above, CO2 has the same effectiveness and dissolves exactly the same regardless of the alkalinity of the water or of it's hardness. Therefore, you should not base your decision to use RO water on CO2 effectiveness at all.
Using RO adds a certain degree of difficulty to any tank, and life is complicated enough so you need to convince yourself that it is the direction you want to go in. Few here except for the hard core discus keeper or dwarf chiclid breeder bother with RO. There is no advantage whatsoever in terms of plant growth unless your tap water is from Lakes Malawi or Tanganyika, or unless your tap water contains high concentrations of toxic metals such as copper.
The ratio of RO-to-Tap would depend entirely on
why you are using it. As discussed above, if you wanted to grow one of the few types of plants that really require soft water you would mix RO to Tap in a ratio that gives you a result say, of kH 4 or lower and GH 7 or lower. It's impossible for me to say what ratio that equates to because I don't know what your tap water parameters are. The same story goes if you are keeping discus or dwarf chiclids and you want to keep the water hardness low. If you are using it for basic purification due to local toxicity (or bacteriological/viral reasons) then you would have to determine what ratio brings the mix to within safe levels for fauna.
Other than the Lake Malawi scenario, these are the only other basic reasons I can think of for using RO. Also, the more RO you use the more likely it is that you will have to add back calcium and other minerals to the water in order to avoid mineral deficiency in the plants
Check the article in the link above and just ask if you need further clarification.
Cheers,