ATO using tap water?

[ianryd]

Let me start by saying I know all the reasons not to do this, but I'm curious if anyone out there has run an ATO off tap water and how successful (or unsuccessful) they have been. I'd like to add an ATO to my 80 gallon system. I lose about a gallon a week to evaporation and do a weekly 10 gallon water change with RODI. I currently top off with RODI by the pitcher. I just wonder with that small amount of water loss and the frequency and volume of water changes could it really be that bad? Again, I know the theory of why not to do this, but am more interested in peoples actual experience in doing this.

 

[Rakie]

Losing 1 gallon per week is nothing. Surprisingly low in fact.. In my 45 cube I lose about a gallon per day.

Have you ever seen whats in your water? Not only lots of harmful chemicals, but there's "acceptable" traces of arsenic in my water, and I'm from a pretty affluent area with pretty good water quality.

I don't know anybody who would willingly use Tap water for anything. Not even for fresh water fish, let alone SW fish, and double that down for any tank with corals.

 

[garbled]

In the olden days before RO/DI was reasonably priced, I used to topoff with tap water.

Had alot of algae in that tank.. Nothing died, but, alot of algae.

 

[Goodair]

Prob better just getting a larger ato reservoir and refilling it when you do your water changes if you lose that little.

 

[User]

Lol, don’t do this unless you get an ICP test on your tap water and know exactly what is in there and what your putting in the tank. My guess is once you see what’s in there, you won’t do it

Build up of toxic chemicals and metals is cumulative. Even 1 gallon a week of tap with 0.01% copper for example will only take a couple months before your inverts are all dead. Not to mention phosphates will make alga go crazy.

I’m topping off 20g in 5 days. I still use rodi, because I sure didn’t spend all this time getting this tank going just th screw myself taking a 10 minute a week shortcut. Turn on rodi unit, walk away. Come back, turn it off.

 

[Rakie]

In the olden days before RO/DI was reasonably priced, I used to topoff with tap water.

Had alot of algae in that tank.. Nothing died, but, alot of algae.

This is true. But back then, people also had much more hearty corals than today. Many corals today are often corals that weren't able to be kept before. To me, that means they're much more sensitive, and might still have horrible problems.

 

[User]

This is true. But back then, people also had much more hearty corals than today. Many corals today are often corals that weren't able to be kept before. To me, that means they're much more sensitive, and might still have horrible problems.

But also, back then, there wasn’t the same types and levels of contaminants in the drinking water supply as there are now.

You could quite easily live in the suburbs and be on a small local supply, and have better water than you can buy in a bottle now. But with increasing urbanization and all of the waste, extra food production, extra manufacturing etc etc that goes with it, water quality across the board goes down.

My water has 29ppm tds. I know right? 0.008ppm of that is arsenic, and 3.26ppm is silicates. I don’t even drink my tap water- or give it to my dog. Why would I keep fish and corals in it?

 

[garbled]

I wasn't suggesting to actually do it. My rationale back then was that my city water was SUPER high in calcium, so, my calcium levels were magically delicious.

I can afford an RO/DI now, and so can anyone with a reef tank. There is no good reason to do that anymore. Also.. the algae. Seriously. It was hard to keep up with. Nobody wants that.

 

[Rakie]

I wasn't suggesting to actually do it. My rationale back then was that my city water was SUPER high in calcium, so, my calcium levels were magically delicious.

I can afford an RO/DI now, and so can anyone with a reef tank. There is no good reason to do that anymore. Also.. the algae. Seriously. It was hard to keep up with. Nobody wants that.

No worries, we knew what you meant

 

[ianryd]

Thanks for the replies. That's about what I expected to hear. Does anyone have recommendations on an ATO unit that is suited for a smaller demand like mine?

 

[Tastee]

Build up of toxic chemicals and metals is cumulative. Even 1 gallon a week of tap with 0.01% copper for example will only take a couple months before your inverts are all dead. Not to mention phosphates will make alga go crazy.

This is an extremely good point. H2O evaporates from a tank. Not much else does. So if you top up with anything except (reasonably) pure H2O everything else will build up. Phosphates. Heavy metals. Most of whatever else is in your tap water. Only water changes will remove that, and even then only by proportion.

So the less WCs you do the more important it is that you top up with RODI.