Small Quantities Of Non-Dechlorinated Water - Safe Or Not?

[FishBlast]

Before this year, I used to just leave the water out over night to lose the chlorine and did large water changes. Now I use dechlorinator for large water changes, but can I just leave a bottle of 1.5L outside and add it few days later without dechlorinating it? For just topping up water, not major water change.

There are no mentions of tap around here having chloramine and if it did, my fish probably would have died by now due to all those water changes done for all those years.

 

[tribalbrit]

I do 40% wc every week and never use dechlorinator. So a little in your case will not cause any problems IMO.

 

[FishBlast]

I do 40% wc every week and never use dechlorinator. So a little in your case will not cause any problems IMO.

I used to do 80% or so before getting dechlorinator once I started doing only partial w/c and the filter's ammonia bacteria at least was still working right and still is.
Before that I used to do 100% w/c with water that stood outside for 3-5 days and my aquarium fish didn't have problems (unlike some wild fish I've put in tap that wasn't left outside overnight and they turned white and died).

I've also heard that dechlorinator might remove some minerals that would be useful, so a bit of non-treated water might add those back (although the calcium will be back too, but is that good or bad? I know for sure I have calcium in water, as it causes calcareous/limestone deposits quite fast)

 

[OldMan47]

Something around 10% of water change is known to be no problem at all without a dechlorinator. If you are changing more than this, I consider a dechlorinator cheap insurance. I have no idea what the maximum change a tank will tolerate is but cannot simply sacrifice my fish to find out.

 

[FishBlast]

Something around 10% of water change is known to be no problem at all without a dechlorinator. If you are changing more than this, I consider a dechlorinator cheap insurance. I have no idea what the maximum change a tank will tolerate is but cannot simply sacrifice my fish to find out.

I think 1.5L isn't even 10% of it. Maybe around 2-3%.
And this water contains only chlorine which seems to evaporate over the days. Before using dechlor, I've had no problem with using the tap water for large w/c. Also, I've tested the ammonia levels before I've started using the dechlorinator and it seems like the bacteria were still doing their job so there's no chloramine to hurt them.

Anyway I added the bottle of water yesterday. Today no signs of fish being affected.

And I still have dechlorinator left for 2 or 3 weekly large water changes, depending how much I'll change next time. But I'll need to buy a new dechlor once I get my next salary, along with nitrite test. Whatever is left I'll either invest in ph kit or in nitrate (or both if I can).

 

[CezzaXV]

Something around 10% of water change is known to be no problem at all without a dechlorinator. If you are changing more than this, I consider a dechlorinator cheap insurance. I have no idea what the maximum change a tank will tolerate is but cannot simply sacrifice my fish to find out.

I agree with this. It's likely quite safe but considering the cost of dechlor (especially if you use a super concentrated one like Prime) its just not worth the risk. Don't forget that the chlorine is going to do more damage to the bcteria than it will to the fish. Serious damage can mean you end up in a fish in cycle.

Too much like hard work for the sake of a squirt of dechlor.

Don't forget things like chloramine which will persist long after the chlorine has gassed off.

 

[FishBlast]

Something around 10% of water change is known to be no problem at all without a dechlorinator. If you are changing more than this, I consider a dechlorinator cheap insurance. I have no idea what the maximum change a tank will tolerate is but cannot simply sacrifice my fish to find out.

I agree with this. It's likely quite safe but considering the cost of dechlor (especially if you use a super concentrated one like Prime) its just not worth the risk. Don't forget that the chlorine is going to do more damage to the bcteria than it will to the fish. Serious damage can mean you end up in a fish in cycle.

Too much like hard work for the sake of a squirt of dechlor.

Don't forget things like chloramine which will persist long after the chlorine has gassed off.

I've mentioned before, I don't have chloramine, but wouldn't want to end up with no dechlor for large w/c and there's almost no way I can get Prime in Romania. I don't trust eBay after what I've seen happening either.

I need to be careful with resources until I can get a new dechlor, else I'll be stuck with less large w/c until next payment.

 

[CezzaXV]

Are you 100% sure you have no chloramine? Do you have a report from your water supplier telling you exactly what's in your water?

In any case, my point still stands - dechlor does a lot more than just remove chlorine.

 

[FishBlast]

Are you 100% sure you have no chloramine? Do you have a report from your water supplier telling you exactly what's in your water?

In any case, my point still stands - dechlor does a lot more than just remove chlorine.

I've checked the water stats on their website and it only mentioned chlorine treatment and the composition was 0.05 for everything else allowed (nitrites and ammonia although they say nitrates can be 50 max).
Here are the latest reports on their website for 05.03.2012:
pH 7.17
Ammonia mg/l 0.009
Nitrites mg/l 0.009
Nitrates mg/l 5.7
Fe 89
Hardness 8.05
Aluminium 29
Chlorine mg/l 0.45

This for our water supply. PH seems to have dropped since the beginning of last year though, it was 7.42. Says it is allowed to vary like this: ≥6,5 ; ≤9,5 but according to the studies of earlier years, it usually is between 7.20 and 7.42.

 

[Tolak]

Water changes of 25% or less using untreated water is more common than you would think, regardless of chlorine & chloramine; http/www.fishforums.net/index.php?/topic/161413-water-changes/

 

[FishBlast]

Water changes of 25% or less using untreated water is more common than you would think, regardless of chlorine & chloramine; http/www.fishforums.net/index.php?/topic/161413-water-changes/

Well, this is just for the topping of water because my plant keeps growing to the top and ends up dried + it adds more fresh water for the fish too. It's not straight from the tap since it still is left outside for a day or up to 3.
Every 5 days I do the large changes with dechlorinator, between 2 and 3 10L bottles (which takes 5 ml of my dechlor if full bottle though I don't fill them to the neck of the bottle).

Speaking of plants, today I'll add 2 river rocks to my tank to hold in place one water sprite my hoplo keeps unrooting. Are they safe though? I've put them in boiled water to soak and then I'll wash them with extreme cold water. Though I still risk ending up with the sprite ruined. Crazy kitty fish can't stop tearing plants apart and carrying them away.

 

[FishBlast]

At least they keep the plant down... He's trying real hard to unroot it again. LOL.