Is my lfs's R/O water snake oil?

[mooman]

I have been purchasing R/O water from a lfs here in that sells it for $0.59/gal. I started using it in order to soften the water in a ten gallon containing a pair of apistos. Recently I began adding tetra blackwater to begin taking the ph down, since the soft water alone wasn't triggering a spawn.

Long story short, I had to add 6x recomended dosage to take ph from 7.2 to 7.0. When I took a sample to the lfs and had them check kh and gh, they said kh was 3 (higher than local tap). He seemed totally unconcerned when I told him it was thier RO water he had just tested, and when he tested the RO water they have in store (went to the back to do it) he said the kh was 1. What could possible cause this to happen?

ps my gh test reads dh=7 on any water I test (rainwater even). Are innacurate GH tests common in hobby test kits?

 

[tjnelson44]

I have heard that some blackwater type additives can raise the tds. Maybe it can affect other parameters too? Is there something in your tank that is altering your parameters such as certain types of rocks or sand? As for the ro water, for a few cents less that you are currently paying, you can just go to walmart and buy distilled water. It will have 0 kh, 0 gh, 0 tds.
Trevor

 

[tjudy]

Additives will most likely increase conductivity, which is a part of the GH equation. As far as the pet store's R/O goes... ask to see the machine and reservoir. I was at a store back east (NC) a few months ago that sold 'purified' water that the led me on to believe was RO... I asked to see their system because they said they could make unlimited amounts per day (yeah right) with little waste. The system was not an RO.. butrather a very good filtration system. The water did not come out pure. I am just geeky enough to carry my Hanna meter on trips with me, so I showed them the error in their statements.

How much water are you buying each week? For about $120 (or less if you go generic) you can buy a good 10 - 25 gpd RO. Go take a look at www.spectrapure.com. They are more expensive, but their quality and customer service are superior.

 

[mooman]

Yeah, I'm starting to consider getting an RO machine for the future (Right now I only need a few gallons per week for changes on the 10g apisto tank). The only thing stoping me is the initial outlay, and the jibes I will get from my girlfriend when I start setting up "that crazy geek contraption". Right now it's an excuse to browse the lfs.

btw got some ro from another store. Tested much better (gh=1, ph=6.4). I will be shopping there from now on.

 

[oldschool]

I never add any additives what so ever to my RO water for my Apistos. There is enough minerals and trace elements left in RO water to be safe. RO does not make 100% pure water. Now if you have a DI in conjunction with your RO then you have a different situation. You should of course do regular water changes so as to not deplete the water of trace elements etc, you need to do this anyway with Dwarf Cichlids! I have bred every Apisto under the sun doing things this way. If we examine the water of the Rio Negro etc it has a conductivity of 5-6 us/cm. Most RO water additives will make water that is much higher. I personally have never understood why so many mess with RO additives. You might as well make less quality water or add some of your wastewater back in. Just my two cents but then again I have bred just about every Dwarf Cichlid from T.candidi, various Dicrosus sp., gibbiceps, elizabethae, pertensis etc. This has always worked. The only additive I add is peat or Oak leaves. To stimulate rainy season conditions and alter pH. Here is a link to an article I wrote regarding water qualituy issues.

http://www.exoticfishfactory.com/new_page_3.htm