What could be reef toxic in my tap water? and how to test for it?

[ceastman]

I was curious if I could do the initial water fill with just tap water? what in my tap water could be toxic to a reef? how could I test for it and then how can I cleanse it if needed?

I just finished filling the main tank and the sump to do the final leak test. I live up in Round Rock and have a water softener, we get our water from the city.

I do have an ro/di unit just haven't set it up yet.

[offroadodge]

I wouldn't use tap water, set-up RODI. You will hate yourself otherwise, JMO

[victoly]

+2 rodi. Its not the only option, but it certainly makes things easier.

[Planeden]

Odds are chlorine/chloramine is the only toxic thing in your tap water. It's possible, but unlikely, there may be large enough concentrations of heavy metals that can be toxic. I think timfish recently said that in many+ years he's never had tap water kill off his tanks.

I did have a friend whose water supply was so concentrated in nitrite over the summer that his fish were getting burned. I think he said it was coming in at 5ppm.

Aside from standard aquarium test kits, I don't know how to test for anything.

[Bpb]

There are a few very experienced people on here that will likely show you examples of tap water tanks that have been done successfully.

Mind you...this is a small minority of reef keepers (that I've met anyway). Tap water isn't just tap water. It's mystery water. The only real way to find out what is in YOUR tap water is to either find out exactly where the source is and inquire about a report that states it's makeup. You're not realistically going to be able to go out and find test kits for every single potentially harmful contaminant that might be in tap water. The benefits of RODI water aren't having "clean" or "pristine" water. You'll still get algae using RODI water. You'll still lose corals and fish using RODI water. The purpose of it is having CONTROLLED water where you can decide what goes into your system. Most of our goals is to come as close as we reasonably can to replicating basic natural seawater levels. It's just easier to start with a blank slate. That's my 2 cents.

I've seen several pictures and videos of tap water tanks that look great. Good for them. My local tap comes out with 100 ppm calcium, almost zero magnesium, 25 dKH alkalinity, and boat loads of phosphate. Would I achieve someone else's results with my tap water? Not likely. And nobody around here does. I'm not from Austin btw. I don't know what y'all's tap parameters are

[Woods]

More than toxins that kill fish or corals, I wouldn't use it due to excess Algae and Cyano outbreaks from people that have used it from what I have heard.

[Wade]

Due to my overabundance of ignorance when I first got into this hobby, I used tap water for years. Also had brutal algae problems for years. Finally pulled my head out of my butt and set up an RO/DI unit. Small investment that reaps invaluable rewards. I got mine from BRS.

[Timfish]

Heavy metals and chlorine is what is potentially harmful. Austin water is pretty clean. Here's the system I've been maintaining for over 5 years with tap water:

Regarding added trace amounts of nitrogenous compounds, mostly ammonium, in water are significantly less than amounts in the food wee add every day.

[Jpowell490]

As others have stated, when I first started saltwater I used tap water as well. I used it actually about a year ago for 6 months with no ill effects.

The worst part of tap water is phosphates. You will come in one day and your water will be green and the sides of your tank will be covered. It is really, really hard to get rid of that short of changing all the water every few days.

RO/DI is worth it. It is initially expensive, but lasts for a long time. I have had my same RO/DI membrane for probably 2 years and my tap water still comes out 001 about every time. Now I like to see 000 TDS, but I will take 1.

I had tap water that read 450 tds that I never used. The tap water I have now read 65 TDS which isn't bad, but was still full of phosphates. It is just a real pain to recover from that once it starts. Takes months.

[Timfish]

Here's a link to DoMa's tank with tap water:

http://www.austinreefclub.com/topic/17762-tap-water/?hl=%2Btap+%2Bwater#entry127584

I've been keeping tanks with tap water, RO and RO/DI for years and haven't seen much difference between them regarding nuisance algae. All of them have algae problems of some kind or other at some point or other and from my experience most nuisanse algae disappear on their own and don't need mediation outside of physical removal.

[Jpowell490]

I think the main thing is that if you have some sort of issue, then you can rule out your water pretty quick if you are using RO//DI. That's a huge issue out of the way immediately.

[ckyuv]

I used tap water to fill my tank initially. I never noticed any issues. I do water changes every 2 weeks so I'm sure what ever poison tap water may contain has been removed from my tank by now. Also if you run carbon it would help clean it up. I only did it because I was to anxious to wait for my rodi to fill my entire tank. If I had to choose of course I'd go rodi but I haven't noticed any negatives from using tap.