Water quality question- Using coralife RO filter system.

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Aquarium Advice FINatic
Mar 4, 2004
King of Prussia, PA
I just purchased a new coralife ro system to filter my tap water for water changes and top offs. The thing seems to work great.

However I am not positive what I need to look for and supplement in terms of water quality.

I currently add a PH buffer that brings my PH level up to 8.2-8.3 range from the very nutral range of 6.5-7 that comes out of the filter. I also realize when I add salt I also get trace elements as well as calcium.

I have ph tester, calcium tester. What other test kits should i purchase and use to check for in terms of this new filter water goign into the tank? Should I be adding supplemental things to get hardness of the water up?
As said many times before never add anything to the tank that you don’t have a test kit for. Even the buffer you add isn’t needed most of the time since the salt mix will bring your ph up to around 8.2 anyways. The only thing you might have to add to the salt mix is a ca supplement to get it closer to 400-450 ppm but unless you have corals that would use it then it’s also a waste.

Just doing 10% weekly or 20% bi-monthly water changes will give you all the supplements your tank needs.
I have a TDS meter to keep an eye on my RODI purity. I got mine for like $22 off ebay and it works great. not a requirement though. certainly your RO is going to be better than tap, so things should only be getting better because of it.
What about IODINE? I have bubble coral and some mushroom coral. I have heard that Iodine could be a good thing to add. Do they make a test kit for Iodine that is not too expensive? Should I even bee concearned with Iodine levels?
I am not real sure about iodine or how much you should add but I do know that if you do add anything you will need a test kit for it and watch the levels.
jasno999 said:
Do they make a test kit for Iodine that is not too expensive?
Salifert Iodine test and it's not cheap but I would still get it if you plan on adding. Again with a proper pwc schedule of at least 10% every other week it would supply the proper trace elements and you wouldn’t have to worry if your corals/inverts/fish were getting the right “quantity” of each and every element.

More experienced reefers sometimes add trace elements but you are asking for trouble in the long run without anyway to test for them if you do not have a test kit for each trace added.
I have a iodine test kit and I also dose iodine. I am still investigating if I am wasting my time or not. I normally tested for iodine about once a month when I first started corals and all levels where fine from the salt mix. Only after my tank got heavily stocked with corals did I see a decline in iodine in the water. I would say if you only have a few corals normal water changes are all you need. If I learn something new stating otherwise I will pass it on.
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