Water Changes

[Corey Shelk]

I used RODI water today set up my saltwater tank. It's a 20 gallon with a few mushroom corals that came in on the live rock, some pulsing Xenia that came in a bag with my snails, green star polyp, 3 astrea snails, 6 (probably less by now) dwarf blue legged hermit crabs, at the beginning of the week 20 (now maybe 5) saltwater ghost shrimp, 3 mollies (I just have them in there to test how Langston does with fish), 1 emerald crab. And finally my main love, Langston, a Caribbean rock mantis shrimp (Neogonodactylus wennerae). I put the ghost shrimp and hermits in there so he can hunt and it's awesome. I add 20 ghost shrimp about every week or so. He has hit the emerald crab once but the crab is fine and loving life and Langston hasn't touched it since. He completely ignores the snails and mollies. So now that you have my stocking, I'm wondering if I can just use tap water treated for chlorine for water changes or if I need to use RODI water? I'm not really invested into my coral, with me starting this as a FOWLR tank but that few things sneaking in. Also soon I will replace the mollies with a clownfish or two.

 

[TheEngineer]

Do you know what’s in your tap water? RODI is more about controlling what goes in your tank than anything else. I know someone who ran a successful tank off of tap water. They switched to a RODI and the tank improved dramatically.

 

[Corey Shelk]

I don't know exactly what's in it. Are there test kits I could use to test for phosphates, copper, flourine, etc?

 

[TheEngineer]

I’d suggest going to a lab and having the tests done. It should be under $100. The other issue is that what’s in your water can change.

 

[Corey Shelk]

Yeah, it seems like the risks are too great. Thank you!

 

[TheEngineer]

Yeah, it seems like the risks are too great. Thank you!

I think the piece of mind from a RODI system is well worth the investment

 

[Corey Shelk]

I've been thinking about it, I'm in college and live in an apartment though so right now I might just have to continue buying it for $.50 a gallon at my LFS

 

[Dom]

Don't automatically conclude that the water from the RODI is good water. The filtering media in RODI filters is consumable and needs to be replaced, the frequency of which varies as municipal water supply quality varies.

Collect a sample of RODI coming from the filter in a cup and take a TDS reading. Ideally, you should see ZERO.

You should also install a flush valve to flush your media after making water. This will extend the life of the filter media.

 

[Corey Shelk]

Thank you!

 

[WVNed]

You water company probably has a water quality report online. The stuff in tap water (there is always some) gets concentrated by evaporation and builds up over time. Your inverts will die first, then corals. They don't die instantly, they just waste away and never thrive. The fish and algae will be fine but after a few years that's all that will live in the tank until you restart it.
I did it that way for more than 10 years. I hauled water too at times.

You can unscrew the aerator on a kitchen sink and hook up a RO/DI. That's what I do about once a week. Then you change it back when you are done. It was money well spent. Things I was never able to keep are doing great like cleaner shrimp. They never lasted more than 2 months in tap water.

 

[HOOPDEEZ]

Yeah if your main love is a mantis shrimp then I would definitely not add tap water! There is most likely copper in it. There are some exceptions but most people will need RODI to run a tank successfully.

 

[Corey Shelk]

Thank you all! I picked up some RODI water today and eventually I'll get myself a unit

 

[Dom]

Thank you all! I picked up some RODI water today and eventually I'll get myself a unit

Test that RODI water. Just because you "picked up" some RODI, presumably a LFS, doesn't mean it is good water.

I would put a TDS meter on it and take a reading.

It may have come from an RODI system, but if the media is depleted, you will get elevated TDS, which can lead to problems.

Always test what you put in your tank when you haven't made it yourself. I once purchased a puffer from a LFS. Out of curiosity, I tested water from the bag and found the nitrates to be OVER 160!

 

[Corey Shelk]

Test that RODI water. Just because you "picked up" some RODI, presumably a LFS, doesn't mean it is good water.

I would put a TDS meter on it and take a reading.

It may have come from an RODI system, but if the media is depleted, you will get elevated TDS, which can lead to problems.

Always test what you put in your tank when you haven't made it yourself. I once purchased a puffer from a LFS. Out of curiosity, I tested water from the bag and found the nitrates to be OVER 160!

That's smart, thank you!