Questions regarding water

[xxPinkFlamingo]

I plan on starting a sw tank here in the next week or two and have questions about RO water. I plan on starting with only fish until i know I can handle corals. My main question is, how important is it to have RO water with fish only? I know with corals it is strongly suggested to have RO water, but are sw fish as sensitive? Once I go with corals is RO or RO/DI better? I plan on having live rock and sand to start with as well. Thanks!

[nightster]

If you start with tap water then it will always be in your system. No matter how many water changes you do some will remain in the tank. The main reason to stay away from tap is the algae it causes due to impurities. So if you want algae then use tap. IMO any saltwater tank should atleast use RO water, that of course is just my opinion. You may be fine with tap water, but I doubt it.

[semper]

You will be fine with tap. Just ask anyone that has seen my tanks

[nacra99]

Depending on where i lived, i have used either one or the other.
When i lived in Louisiana and water is hard and had high TDS i had to use RO water.
Since moving to houston (around the galleria area) where the TDS is significantly lower that previously, i have always just used 100 tapwater.
But make sure that your top-up water is ALWAYS RO water.

I do warn however that tapwater seems to cause a significantly larger diatom and algae bloom when just starting out and cycling. Probably because of the dissolved nutrients. The solution seems to be running a macroalgae refugium 24/7 during the cycling process. The macrolagae will help suck up nutrients.

Good luck!

[Darbex]

Its hard enough controlling algae in RO/DI water but to use tap water for creating SW, IMO, is asking for trouble to start one day. To each his own.

[RocketSurgeon]

You will be fine with tap. Just ask anyone that has seen my tanks

We are not saying that it can't be done. It's just the exception to the rule.

When there is an algae outbreak, or a question about a sickened coral, it makes it so much easier to rule out UNKNOWN water contamination if your source water is pure.

[xxPinkFlamingo]

I planned on using tap water until I decide to go with corals. Before I added corals I was planned to do multiple water changes with RO water. Would that work?

[RocketSurgeon]

If you start with tap water then it will always be in your system. No matter how many water changes you do some will remain in the tank. The main reason to stay away from tap is the algae it causes due to impurities. So if you want algae then use tap. IMO any saltwater tank should atleast use RO water, that of course is just my opinion. You may be fine with tap water....

...I do warn however that tapwater seems to cause a significantly larger diatom and algae bloom when just starting out and cycling. Probably because of the dissolved nutrients. The solution seems to be running a macroalgae refugium 24/7 during the cycling process. The macrolagae will help suck up nutrients.

Good luck!

Its hard enough controlling algae in RO/DI water but to use tap water for creating SW, IMO, is asking for trouble to start one day. To each his own.

We are not saying that it can't be done...

Will it work? YES. Is it recommended...NO.

[nightster]

I guess it depends on how good your tap water is mine is horrible lol.

[Darbex]

Yeah my tap water TDS is about 300-400. Thats way to uncomfortable for my taste. My RO/DI water is 0-4 TDS. That alleviates the worry of contaminants.

[xxPinkFlamingo]

What is TDS?

[RocketSurgeon]

What is TDS?

Total Dissolved Solids = checked with a TDS meter.

[trbkrb]

How big of a tank are you planning on? I'll run you some RO/DI water if you want it. IMO I would do like the others have said, and start with the best quality water you can get, just to be on the safe side.

[BeefyG]

By the way, those watermill express places filter their water with RO/DI. The one by my place is 25 cents a gallon.

[trbkrb]

By the way, those watermill express places filter their water with RO/DI. The one by my place is 25 cents a gallon.

They are only RO water. You would not want to drink RO/DI water, it has no taste and some have even said it is not healthy to drink. I know mine tastes strange when I get a mouthful from using a hose to siphon it off into a bucket. The only bad thing about those places is you usually don't know when it was serviced last, and you really need a TDS meter to test it. I just checked their website, they do service them daily, but only guarantee a TDS of less than 50. I get my RO water down to under 4 ppm and sometimes it is almost zero, but it is for sure zero after the DI stage.