Water problems (see if you can work this out)

[a_free_bird73]

I am really struggling to work this out.

I have a small 10G tank and a 150G tank. Our water here is very clean, soft with very low mineral and heavy metal content. It is also chlorinated lightly and there is no chloramine use.

I have never used dechlorinators on my large tank and never had a problem (chlorine immediatly gets oxidised in a tank of that size with a lot of organic content). For the small tank it has been a different story. For a while, I could not keep a fish alive especially babies. I then switched to using aged water from my large tank and had no problems. Yesterday, I decided to trial a 50% water change with tap water that has been left for 24 hours. This morning my baby Discus (about 1.5 months old) are all suffocating which is the problem I used to have before I started using aged water from the main tank.

Can you explain this? lets see your theories!

[Slappy*McFish]

Let the water age a bit longer...or use dechlorinator.

[RTR]

Have you tested the 24 hour aged water for chlorine? I age my water normally 48 hours with heating and circulation. Just 24 hours would not be enough at all times with my water supply. It might not with yours either. Anytime the utility does any pipeline work, they boost the level of disinfectant a bit.

[beviking]

Would the "...heavy metal content." have something to do with it? Just how heavy and what metals??? Perhaps a 25% water change with the aged water would have been a wiser chance to take?;)

[Cearbhaill]

Can you explain this? lets see your theories!
Inconsistency in tap water parameters.
Municipal water purification methods might be changed seasonally or for many other reasons.
First step would be to get in touch with them.

[a_free_bird73]

Yes I have tested the water for chlorine and it is undetectable (where as it is detectable from the tap).

I will try to aerate the water for 48 hours and see how I go.

As for the heavy metal content, it is extremely low (in ppb - ppt). Melbourne water is known to be one of the cleanest and also softest (GH averages 0.8). Even the worst days will still give numbers well below danger threshold according to the detailed annual water report.

If aging the water for 48 hours does not work I will try adding EDTA to be absolutly certain that it is not heavy metal related toxicity (metal toxicity has an exponential effect the softer the water gets)

[yashinfan]

Why don't you just use dechlorinator like the rest of us folk? :o

[ewok]

you know what screams out to me here? ph

test both tanks ph, and the tap water, maybe even before and after aging. by using aged (read junk) water from the big tank you're making a cycle of lowering the smaller tanks ph. by doing a 50% tap water change you might have effectively ph shocked your fish.

the smaller tank will lose ph by the nitrogen cycle and so will the larger. by adding depleted water from the large tank into old water in the 10g tank you have probably removed the buffer and lowered the ph over time.


(chlorine immediatly gets oxidised in a tank of that size with a lot of organic content).

that's a bad statement. i sort of doubt that truly happens. what you are seeing with the larger tank is a function of "dilution". because of the volume of the larger tank the water dilutes the chlorine until it outgasses and the volume of contaminants is smaller overall. more than likely the larger tank also has stronger filtration to push the water around and help it outgas quicker and it also has a much larger surface area for it to outgas from.

i'd quit playing russian roullette with the dechlorinater guesswork and just use it.

edit: for clarity