hot tap water

John G · Post by **John G** » Thu Mar 26, 2009 8:56 am

I have a couple of aquariums with no heaters, so when I put water in them on cold days I have been using a mixture of hot and cold water, to get the temperature up at least to the 60s.

Is this a bad habit of mine? I have read several places that one should never drink or give babies water from the hot faucet, as it is likely to contain lead. For example, an article in the NY Times said "that even newer plumbing advertised as 'lead-free' can still contain as much as 8 percent lead." Apparently when water goes through a hot water heater it dissolves more contaminants, like the lead.

So does anyone know if the lead is likely to hurt aquarium fish or even worse, plants?

MaggieBennett · Post by **MaggieBennett** » Thu Mar 26, 2009 9:11 am

I always mix cold and hot water to the appropriate temperature for the tank. I do let the hot water run for a minute or so to flush out some of the water that's been sitting in the pipes, though, before I start filling. Haven't had a problem yet!

chris_todd · Post by **chris_todd** » Thu Mar 26, 2009 11:20 am

I am not a water chemist, but I always assumed it was worse for the fish and plants to get a blast of cold tap water than to get a few extra contaminants from mixing hot and cold water. So when I'm doing water changes, I've always tried to mix hot and cold water to get the temp to where it feels roughly the same to my hand (so it's probably within 3 degrees of the tank temp).

Now that you mention it, though, I have noticed that my two rainbow sharks in our 65g lose some of their color right after a water change. It is my understanding that these fish get very black when they're happy (and that's how they usually look), and get more grey when they're stressed. Not sure if that's because of something in the water, or if they're crotchety old fish that simply don't like change.

Home lead tests are available, perhaps in the grocery store or home improvement stores, though I honestly don't know whether they're at all accurate.

Sorry, I'm not sure if this post is at all helpful. Perhaps Sean, or someone with a better knowledge of water chemistry has a more informative comment?

Cristy Keister · Post by **Cristy Keister** » Thu Mar 26, 2009 12:13 pm

Most of the water conditioners also remove metals - check the label on yours.

I've been using simple sodium thiosulfate on my downstairs tanks and have always mixed in hot water without obvious trouble. However, I doubt that metals are something that would affect the fish right away, but perhaps with a build up over time. Like Chris said, I think that a blast of cold water is more likely to harm the fish, particularly when they are kept in very warm water like my Discus.

dSerk · Post by **dSerk** » Thu Mar 26, 2009 1:22 pm

I'd heard that HOT tap water looks cloudier than COLD tap water because of metal ions picked up while the water was in the water heater. I add lukewarm, treated tap water during my water changes and I use cold water if the water's going to sit for a couple days.

Don't some people use those lead strips for weighing down bunches of plants in their aquarium? I guess I'd assumed that lead wasn't so bad for fish.

John G · Post by **John G** » Thu Mar 26, 2009 2:32 pm

Cristy Keister wrote:Most of the water conditioners also remove metals - check the label on yours...

According to the Seachem web site, Prime will "detoxify any heavy metals found in the tap water at typical concentration levels." I guess it hinges on what "typical" means, but it does sound like I don't have to worry if I use Prime, which I usually do.

SCMurphy · Post by **SCMurphy** » Thu Mar 26, 2009 2:37 pm

It depends how old your hot water heater is. Anything installed in the last 20 years is not going to be a problem. Older then that I'd start to worry a little.

DelawareJim · Post by **DelawareJim** » Thu Mar 26, 2009 3:56 pm

SCMurphy wrote:It depends how old your hot water heater is. Anything installed in the last 20 years is not going to be a problem. Older then that I'd start to worry a little.

Smirk. Always the droll Yankee aren't we?

Cheers.
Jim

seiji64 · Post by **seiji64** » Thu Mar 26, 2009 4:16 pm

Does "detoxifying" heavy metals also make my dosed Iron and other micros unavailable to plants? I always dose micros after a water change. Should I wait a day before dosing them?
Doug

RTRJR · Post by **RTRJR** » Fri Mar 27, 2009 9:53 am

I am stiill curious about what 'detoxify' means re:metal ions.

No conditioner can or does "remove" heavy metal ions - conditioners are not RO membranes, nor are they nuclear reactors. They may complex metal ions by chelating them or alternate chemistries, but that is not eternal - what happens when the chelator or other agent breaks down? Those binders are hardly eternal. We all know that chelatted iron has a very limited lifespan in our tanks.

If conditioners precipitate out metal ions as the metal or as salts, fine, that puts them in the substrate or filters. If they were solulble enough to dissolve in the water initially, can they do do so again in the tank?

Ions cannot make water cloudy. Ions are dissolved, we cannot see them. dissolved gases coming out of solution can make water cloudy briefly. suspended solids can also make water cloudy, such as when things precipitate out of the water.

Is there really such a thing as a20-year-old water heater? If so, please let me know the brand if they are still made and available.

I am curious - how many folks actually do the suggested maintenance on their hot water heaters?

And yes, I do mix hot and cold water, even though my reservoirs could do with cold-only.

hot tap water

hot tap water

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