What the...tap water safe for reef tanks?!?!?

[Norboo]

I was doing some research on tanks and biocubes and came across this video. 

 

Did I miss something while I was away?  Tap water safe for reef tank?

 

 

 

In this video:

 

 

At about 6 minute mark, he washes everything out in the sink with tap water and at about 15 minute mark, he puts coral into the same container he used in the sink to put coral in there. 

 

I just watched in horror. 

[YHSublime]

You go first!

[surf&turf]

I use tap water.

[Jason Rhoads]

I use tap water for water changes; RO/DI for top off though. 

[Brian Ward]

I rinse equipment in tap water. I figure it's better than anything else that's easily available for rinsing. But filling, water changes, and topoff are all RO/DI. I figure the contaminants in the few drops of tap water are easily diluted away in the tank.

 

Tap water can be dechlorinated but you'll find trace amounts of copper (esp if you have copper pipes in your house), lead, etc. that the RO filter pulls out. I'm not sure if dechlorinators are able to pull out chloramines or only the chlorine portion. If only the chlorine portion then you're leaving ammonia in the water. These things are generally considered bad for corals.

 

I use tap water for water changes; RO/DI for top off though. 

I'm not really sure I understand this? If you're introducing tap water in large quantities for water changes, why not just top off with it and do away with your RO/DI system entirely? I'm not sure if there's much to be gained.

[Jason Rhoads]

I'm not really sure I understand this? If you're introducing tap water in large quantities for water changes, why not just top off with it and do away with your RO/DI system entirely? I'm not sure if there's much to be gained.

 

Good question!  Hopefully the below will explain my reasoning a bit:

 

The reason I use RO/DI vs tap for top off is similar to the logic of not using salt water for top off (i.e. using salt water in a top off would raise your salinity due to the addition of the salt remaining from any evaporated water you are replacing and the new salt in the water you are adding).  I use the more-pure RO/DI water as replacement water to avoid a build up, in a similar fashion, concerning unwanted elements.  

 

When doing a water change I am essentially trading water which contains the same (roughly) quantities of elements as that which I am removing (not considering those elements which were used in coral growth).

 

The main driver behind my using the RO/DI for top off water is that I do not like the rejection rate of an RO/DI unit, so I try to only use it where I feel I will see the most benefit (e.g. using it to make pure top off water).  I have been running my tank like this for years with no realized ill effects (I keep mostly SPS).             

Edited December 3, 2014 by Jason Rhoads

[Brian Ward]

Out of curiosity, what do you do to treat your tap water? What county are you in? City or well?

[Origami]

I have no problem with the video. Rinsing the filter sponge out in fresh tap water is fine (just wring it out well). The loss of a few bacteria is not harmful to his overall filtration. Also, reusing the container at the back end to hold a few corals is fine, too. If you'll notice, it's an empty container that he's filling with tank water. The amount of residual fresh water really is minimal when the container is empty. Just a few drops worth that is very quickly diluted.

[Jason Rhoads]

Out of curiosity, what do you do to treat your tap water? What county are you in? City or well?

 

I use Prime and let it sit/mix for 24 hours before I do the water change.  

 

I am in Prince William County and on city water.  I also used this method when I lived in Fairfax county (one year); I was on city water there as well.   

[JeffG93]

I used (dechlorinated) tap water exclusively in my first tank for about 4 years.  Lots of algae, sure, but fish and corals were just fine.  

[paul b]

Some tap water is great, some is not.  When I got New York City water I used that in my tank for about 10 years.  No problem, but when I moved to Long Island where we have well water, well, not so good.  My tank almost crashed 3 times when my town added zinc orthophosphate to the water to control corrosion in the pipes, it also controls corals from living in your tank so now I use RO/DI water.  But I rinse everything in tap water.

[Jason Rhoads]

it also controls corals from living in your tank so now I use RO/DI water.

 

Classic!

[DuffyGeos]

I wash everything in tapwater, filter socks, filter pads, buckets, and nets. I figure it is such a small amount it really does not matter. Half of the things dry out in rotation (different filter socks or pads) before they would go back in the tank anyway so don't think it is a big deal. Top off & water changes are all RO/DI.

[BowieReefer84]

My friend uses tap water (well water?)  His coralline algae growth is amazing.

[smallreef]

I had always used tap water till I moved here.

Out in Washington state, the water comes from underground aquifers and is not treated with any chemicals unless a high level of choloform (sp?) bacteria is found...

Here with all the chloramines s such I run a full rodi....

Edited December 3, 2014 by smallreef

[zygote2k]

I service a Vienna tap-water reef tank and it has amazing coral growth. 

[Enkay]

I use tap water. I have not had any issues over the past year or so. Fish are fat and healthy and so are the corals. The only thing is I do get some brown algae on the glass which I have to clean every week as part of maintenance. But IMHO, its a lot less than running a RODI system.

[quang]

Some tap water is great, some is not.  When I got New York City water I used that in my tank for about 10 years.  No problem, but when I moved to Long Island where we have well water, well, not so good.  My tank almost crashed 3 times when my town added zinc orthophosphate to the water to control corrosion in the pipes, it also controls corals from living in your tank so now I use RO/DI water.  But I rinse everything in tap water.

 

someone mentioned to me the other day that New York City is #1 for cleanest, highest quality tap water. that blew my mind

[paul b]

That's because the NYC water tunnels are over 100 years old and no one has gone into them in 50 years because they are collapsing.  Now we have new tunnels and I am not sure about the water as it must have all sorts of construction debris in them but I am not sure

[treesprite]

The tap water here is full of phosphate and nitrate.

 

I would like to know how many people using tap water live in rental units versus numbers using tap water who live in their own houses.

Edited December 27, 2014 by treesprite

[gmerek2]

That's because the NYC water tunnels are over 100 years old and no one has gone into them in 50 years because they are collapsing.  Now we have new tunnels and I am not sure about the water as it must have all sorts of construction debris in them but I am not sure

Viagra is still getting into your tank somehow with how often your fish spawn. I think Viagra isn't digested in the human body and the waste water treatment plant isn't able to remove it. On a serious note I don't think it's worth the risk and the cost of RODI water is minimal. City water is proven to have medications in it, phosphates and nitrates and it's just not worth the risk

[rtelles]

Downtown dc resident here. Used to purchase premixed saltwater before I picked up a rodi unit, which I now use for water changes/top-offs. That said, my unit shows a tap reading of anywhere between 10-20 tds (I assume the reading is correct) which is way lower than I expected. I used to top off with distilled unless I was lazy and used tap+prime. Never noticed much of a difference aside from a negligible bit of extra algae growth.