Use of Dechlor when filling from Hosepipe?

So if the dechlor bottle says 5ml treats 10l i assume they're talking of water seperate from the main holding tank,if you treating directly into the tank are you not throwing the measurements out the window because you are no longer treating 10l but 50l or whatever is in the tank plus whats been added?

 

@jedigenie I just deleted my entire Inbox so you can PM now

 

That is a very good question...

So now that we have eliminated the irrelevant stuff, let's make this more technical. How does dechlor work? If I have some water with chlorine and I add some dechlor according to instructions and within a short while the chlorine is gone. Now if I have water without chlorine and I add dechlor what happens then? Does it just stay there in the water? If I now add water again which does contain chlorine, will the dechlor then react with added chlorine? In other words, it kinda hangs around until it has something to do. Or not?

 

Excuse my ignorance, but will the amount of dechlor added to the tank at this stage affect the fish in the tank in anyway?

 

Aaah... I see where you are going with this Laure. This is a good question!! If I do a 50% water change on my tank... that's 125litres... I then only add enough Dechlor to treat 125litres... BUT I am in fact adding it to 250 litres, because I am adding it to my tank prior to topping up (with hosepipe). Now am I in effect diluting the dechlor before it has a chance to work on the new tap water, or is it just as effective.

MOST dechlor's are non-toxic to fish. They'd have to be because we add it to the tank in anyway

 

Chlorine is a molecule and therefore cannot be broken down but dissipated into the atmosphere(air). You can dissipate chlorine through UV exposure, de-chlorination or via oxyidation where by the chlorine molecule attaches itself to the oxygen molecule which is then dissipated into the air.

Hope this helps.

 

seems to me this whole problem is irrelevant if you just use a bucket.

 

I'm glad the buckets at your house fill themselves up with water, but at my house if I want to use a bucket I have to fill it up with a hose pipe...

 

@Zoom

More confusing questions: so if I fill the tank up with tap water first, and let's say I have a 200L tank and do a 50% WC, I now dilute the Cl in the tap by 50%. But that is irrelevant, as the instructions never indicate the ppm of chlorine it treats. It merely refers to litres/gallons of water to be treated, regardless of the Cl ppm. So I think if you do this then you still have to add dechlor for the entire tank volume. Unless I miss something here. And getting back to my earlier question. What does dechlor do when there is no Cl in the water? Wait for Cl to arrive and then react?

 

i must admit hose-pipe method has always been very tempting to me, doing water changes on 3 tanks (combined volume possibly 600L or thereabouts) but was always to scared to try..

but considering that i do 10% twice a week, i might try it...

what i can add is that there was a video advert a while ago about this python "spill free" system that shows them using a hose to fill up, and they show that you can add a few drops of dechlor as the water is pouring from the hose into the tank, virtually at the same time..

i dont know if any of you saw it but i think there may even have been a post about it a few weeks ago..

 

sorry guys, its actually called a python "no spill" and not spill free

 

I actually saw one of these in an LPS in fourways the other day.

 

Yeah that is pretty much the system I have in mind, except you don't need to buy the python. I vacuum my tank with a hose pipe. What I do is connect one end to a tap and place the other in the tank and make sure it is secure so it does not move around or disturb the substrate. I then open the tap to force the air out. Then I disconnect the end from the tap and drop it in a flower bed outside. So I syphon water out. Now, what I want to do is just connect the end outside to the tap again and fill up that same way. The dechlorinator's use is what confuses me...@Zoom, any thoughts on the questions I posed earlier before we got interrupted by another "bucket"

 

As I understand it, and I can be proven wrong here, if there is no Chlorine to bind, then the Dechlor will bind with any 'Heavy Metals' in the water, so I assume that this means it could start to bind with some of the ferts in the water too? Again I make clear that I am not a Chemist, and cannot remember most of my A level chemistry, so could be completely off the mark?

I'm sure the Dechlor will remain active in the water column for a short length of time, but after a while, will loose its effectiveness to bind Cl (assuming it has not bound with the heavy metals), but this would again be my minds understanding, and not 'gospel truth'.

I think in order to answer this we could do with a Chemist (or at least someone with a chemical understanding) to answer? Maybe @Dirk Bellstedt can help if he manages to get a free moment?

Regards
G!

 

The Aqua Master Dechlor says on the bottle that it removes upto 3.0ppm of combined chlorine and 1.3ppm of free amonia this is with the prescribed dosing i am assuming. and there website spec says that unreacted AM Dechlor is stable and unless its removed with granular activated carbon it will be available to react with ammonia until exhausted.

I dont know if this helps or makes things more confusing!

 

@Laure, i think big g has it right that we may need dirk to answer this one. You pose a very valid question.

Let me reassess the question:
you want to determine if the dechlor will be effective if used in the hosepipe filling method, and if there is excess, what happens to it?

My mind says that even doing the bucket bragade may also have excess dechlor in any case?

Sent from my Tablet using Tapatalk

 

Most liquid dechlorinators are composed of sodium thiosulphate.Sodium thiosulphate reduces chlorine to chloride.
The chemical can also be used to reverse the effects of cyanide poisoning.Pretty useful.
Found this:
http://en.wikipedia.org/wiki/Sodium_thiosulfate
It is harmless to fish unless a ludicrous overdose occurs.

 

@Zoom the question is this:
If I add water from the tap into the tank, I obviously add water with a certain level of chlorine. The water already in the tank is chlorine free. If I do this with a 25% water change, I will reduce the concentration of chlorine in the water from the tap. Let's say we have a 100L tank which now has 75L of chlorine free water and I add 25L of water with 3ppm chlorine, which I think is probably a reasonable level of chlorine to expect in the tap water. If my maths are correct, we should end up with 100L of water with a chlorine level of 0.75ppm. Quite a difference already; but still there is some chlorine in the tank. However, this low level could be why so many people use the hose pipe straight from tap method without any issues. But what if there is a chlorine spike one day? So I guess it is probably better to add dechlorinator.

Now we get to the question. If I add dechlorinator before I add the 25L of water, it will be added to 75L of water without any chlorine. Most good dechlorinators also remove ammonia, so I guess it will start working on the ammonia in the tank and will keep doing this until it is exhausted. This is because there is no chlorine. Then I add the 25L of water and suddenly there is some chlorine and it can start reacting with the chlorine and reduce it to chloride. The hand in hand question here is how much to add? Do I add dechlorinator for 100L or for 25L?

 

I have one question: adding tap water to your take before add dechlorinator... during this time, would the chlorine in the water not have killed off bacteria as some of this water would have already started circulating through the filter/s before dechlorinator is added?

 

Thats why as stated earlier in this thread, most people switch off circulation to the sump/filtration system during a water change! This then prevents bacteria in the sump being killed off. Any that are killed in the tank will soon be replaced once the sump is back up and running!

Regards
G!