Using tap for reef tanks

[Koh23]

Sure u can use tap water, i saw tanks running on 300+ tds in tap water, and doing great.

None of them, sadly, for various reasons didnt pass 12 months mark, for reasons that dont have anything with water, so, in short term everyrhing is ok, but without knowing what lies around corner in long term.....

Sometimes, if you can do sometning, doesnt mean you should do it.....

 

[Lyss]

I liked the control I have with RODI in my reef so much, I switched to using it and remineralizing it for my FW tank.

The first thing I bought when I decided to start my reef tank was an RODI unit and set it up under my kitchen sink. I honestly don’t really understand why some ppl are so put off by the thought of having to get one and use it in order to keep a marine tank. And the idea of putting salt mix into tap water seems to me like a recipe for having trouble keeping params stable.

 

[Randy Holmes-Farley]

I'm in the process of setting up my first reef tank, and I am wondering if I can get away with using tap water instead of RODI water.

I live in Colorado, which means I'm at the top of the watershed, and the tap water quality seems generally quite good. Using API tests, ammonia, nitrite, and nitrate are all at undetectable levels, carbonate hardness (kH) is 1-2 degrees, general hardness (GH) is 3-4 degrees, and pH is around 7.4-7.6. I use tap on all my freshwater tanks without much of a problem. I have no idea what calcium, magnesium, and phosphate are.

I think I'll buy more tests (e.g. calcium, magnesium, and phosphate) and a salt mix, mix up some saltwater with the tap, and test it. If everything looks good I'll probably try using tap for the time being. I'm hopeful that the low initial alkalinity will mean the mixed saltwater will be pretty low. I use seachem prime as a dechlorinator.

The only things I'm worried about missing are copper and silicon. Local water quality reports say that the 90th percentile for copper measurements done in the water district was ~0.1 mg/L. This seems somewhat high. However, I've been keeping dwarf shrimp and pagaoda snails for years in this tap water which seems to indicate that the copper levels aren't too bad? For silicates I have no idea. My freshwater tanks all get diatoms when they first start up, but they clear like normal as the tank ages same as any other tank.

For reference, I only plan on keeping soft corals and LPS in this first tank.

Tap water works fine in some cases, and not in others. Without an analysis of the water, it's a risk that you have to decide if you want to take.

 

[Randy Holmes-Farley]

Honestly, this is what I'm gonna do. My tank is just a 12 gallon aquapod. I can make all the mistakes. If it really isn't working with the tap I'll switch to RODI, but I think it would actually be nice to at least try. There is no immediate obvious reason my tap won't work based on the tests I've already done. Of course, if something seems really wrong with the water after mixing (e.g. the calcium ends up being 800 or something) then I'll get an RO unit.

You asked for advice, then 2 h later say it doesn't matter what folks might say, this is the plan. Nice.

Even if you decide to use tap water, there are good ways to do it, and much less optimal ways.

 

[Sleeping Giant]

Use Prime with tap water to dechlorination and your good to go.

 

[Randy Holmes-Farley]

Use Prime with tap water to dechlorination and your good to go.

I would give more advice than that on how to avoid copper, for example

 

[Lyss]

The idea is to set ourselves up for success when we are just starting something as challenging as a reef tank, is it not? The only way I see the Op setting themself up for success here is to either do what nearly all of us have done from the start and use RODI, or have a full analysis done on the tap water -- not just relying on API tests -- and make a decision based on those results.

I've personally reached and just barely crossed the 1-year mark for my tank, and after hearing so much about how most new folks don't make it past a year I feel like making informed decisions at the start helped me to make it over that one-year mark. I think if someone is serious about wanting to succeed, making informed decisions is key.

 

[Sleeping Giant]

I would give more advice than that on how to avoid copper, for example

Oh wow, didn't see the copper issue.
Go for the rodi or RO water from a water vendor. I wouldn't use that tap water.

 

[Randy Holmes-Farley]

Oh wow, didn't see the copper issue.
Go for the rodi or RO water from a water vendor. I wouldn't use that tap water.

He doesn't know if it is an issue or not. It's just a risk unless he measures it in his own home.

 

[zdrc]

I trust the API ammonium test. I'm keeping some pretty sensitive freshwater fish without problem. I do large weekly water changes, and I think I would be seeing some problems if I had nonzero ammonia in the tap.

I think I'll get an ICP on the tap. I'm interested what I'll find. I doubt I have a lot of copper because I've had luck keeping dwarf shrimp, but perhaps ocean inverts are more sensitive to copper than freshwater inverts. I can't really find any substantial evidence that that's the case though.

One thing I didn't think about was wanting RODI for the ATO. I don't really like the idea of topping off with non-RODI water. Still I think I'll try it and see how it goes. If I get some alkalinity creep I'll switch to RODI. As someone already mentioned, Jake from Reefbuilders uses the CO tap, and I think he's in Denver, which is more metropolitan than where I am. In addition, I think my LFS uses tap too (with a carbon filter). They said that post-salt mix, the alkalinity runs at about 10 degrees. They seem to be growing SPS without a problem.

 

[Randy Holmes-Farley]

I trust the API ammonium test. I'm keeping some pretty sensitive freshwater fish without problem. I do large weekly water changes, and I think I would be seeing some problems if I had nonzero ammonia in the tap.

I think I'll get an ICP on the tap. I'm interested what I'll find. I doubt I have a lot of copper because I've had luck keeping dwarf shrimp, but perhaps ocean inverts are more sensitive to copper than freshwater inverts. I can't really find any substantial evidence that that's the case though.

One thing I didn't think about was wanting RODI for the ATO. I don't really like the idea of topping off with non-RODI water. Still I think I'll try it and see how it goes. If I get some alkalinity creep I'll switch to RODI. As someone already mentioned, Jake from Reefbuilders uses the CO tap, and I think he's in Denver, which is more metropolitan than where I am. In addition, I think my LFS uses tap too (with a carbon filter). They said that post-salt mix, the alkalinity runs at about 10 degrees. They seem to be growing SPS without a problem.

When you use tap water, and when you take a sample for analysis, let the water run long enough that you are getting fresh water from the street pipes, not any water that was sitting in your home pipes overnight. That's where copper and lead come from. Water sitting overnight or longer in your home pipes would be the worst to use from a copper perspective.

 

[Pale Morning1]

I have been running an Evo 13.5 for 14 months. I do weekly 3-4 gallon water changes using tap water. The tank is at work and I do not have the availability to set up RODI system. I do treat the water with Prime before adding to the tank. To date I believe the tank is healthy. Phosphates are a little higher than I would like at .18 and I do attribute that to tap. 4 fish, two of which have just passed the 1 yr mark in the tank all seem healthy. I do have basic corals but all are growing. Several have been in the tank coming up on one year. That being said if I set a tank up at home I would spend the money on a RODI just for peace of mind. But with tap it can be done.

 

[CrimsonTide]

An aquatic life RODI Buddy system is like $60. Doing small amounts of water it will last a long time. However if you get your water tested find nothing super harmful I would say you are probably okay to have some success. It might now be the best option but it would be an option to use the tap.

 

[AnotherReefHobbyist]

I think a lot of people here don't understand how good Colorado water is. I also live in Colorado, and my tds is only 40 going into the rodi machine. Ovbiously this could be all terrible things, but I did run a reef successfully for 6 ish months, before I decided that I should just switch to rodi because everything else was so expensive and water wasnt going to be my failure point.

I say you dont need it to start out, just keep in mind that if you stick with the hobby, you will probably get one. Everything else is so expensive, just this little bit of insurance is nice.

 

[Lyss]

I think a lot of people here don't understand how good Colorado water is. I also live in Colorado, and my tds is only 40 going into the rodi machine. Ovbiously this could be all terrible things, but I did run a reef successfully for 6 ish months, before I decided that I should just switch to rodi because everything else was so expensive and water wasnt going to be my failure point.

I say you dont need it to start out, just keep in mind that if you stick with the hobby, you will probably get one. Everything else is so expensive, just this little bit of insurance is nice.

I mean, I live in NYC and my TDS is also 40 going in, but I still would have the analysis before just doing it, especially as a new reefer. In the end I personally bought an RODI, started that way, and did not consider using tap.

 

[Randy Holmes-Farley]

I think a lot of people here don't understand how good Colorado water is. I also live in Colorado, and my tds is only 40 going into the rodi machine. Ovbiously this could be all terrible things,

Denver water reported that 10% of homes show copper above 140 ppb in the winter, and some even exceed the action level for lead.

https://www.denverwater.org/sites/default/files/water-quality-report-2021.pdf

 

[cpalminteri]

LOL hey since this thread is mostly useless now, don't mind if I jump in. My LFS had told me that it wouldn't be terrible to start the tank with tap and just make sure going forward I use RODI...... So now what... it's almost done cycling, should i start testing for copper and other stuff? Should I just leave it as is and when I do my big water change in a few days change maybe like 40% using RODI?

 

[Koh23]

Maybe its worth to mention, fw and sw are not the same, what works in fw tanks probably dont work equaly in sw.....

So, argument "i have fw tank with tap water" is very similar to statement "water is wet"....

 

[Randy Holmes-Farley]

Maybe its worth to mention, fw and sw are not the same, what works in fw tanks probably dont work equaly in sw.....

So, argument "i have fw tank with tap water" is very similar to statement "water is wet"....

In all seriousness, it's just incorrect to express any idea about tap working or not except that it sometimes works fine and sometimes not.

The fact that anyone made it work is meaningless, unless you contend it can never work, and the fact that anyone failed is meaningless unless you contend it always works.

 

[Unitylover]

Our water is so good that I almost prefer it over bottled to drink. Is long islands' water good for saltwater?