# Water Changes



## Worshiper (8 Jun 2015)

Hi guys,

I wanted to know if it is okay to perform a 30% water change about an hour after the lights go on(approx 2 hours after co2 goes on),

The reason I ask is I need to do some water changes, however, the lights timer goes on  an hour before I get back from work. Do you reckon I change the timers for a couple of days?

Thanks guys!


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## ian_m (8 Jun 2015)

I have changed 50% water in the evening before, when CO2 & lights have been on for hours and not suffered any issues. Just remember to turn CO2 off when filters are off if using inline diffuser, so as to not fill pipes with CO2 and much much more importantly ensure CO2 is back on when finished.  (whoops forgot that once).


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## Worshiper (8 Jun 2015)

Thanks Ian. I had read somewhere that it affects photosynthesis.. and it also causes a change to the Co2 levels which aren't good for the plants.



ian_m said:


> ensure CO2 is back on when finished.  (whoops forgot that once).



yeah  i once forgot to switch the filter back on  .. for 8 hours! no adverse effects faced tho.


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## ian_m (8 Jun 2015)

Worshiper said:


> I had read somewhere that it affects photosynthesis.. and it also causes a change to the Co2 levels which aren't good for the plants.


It may do, but as only for hour or two makes no odds. Also generally fresh tap water, especially in hard water areas, may be already loaded with CO2 (and O2), which is why you can sometimes get monster plant pearling after water change.



Worshiper said:


> yeah  i once forgot to switch the filter back on  .. for 8 hours! no adverse effects faced tho.


I had no power for 3 days after house RCD tripped whilst away due to a supply neutral fault. Tank was less then 16C when I got back, just turned everything back on, tank & filter all fine. And yet you meet people who put their filter intake and outlet pipes into a bucket of water so they keep their filter running during tank maintenance so as to not make their filter anaerobic or starved or cold or some other reason....

My favourite is not turning back on, is the heater after water change...occasionally running for a week with no heater and tank running below 20C. Fish all appear fine but plants didn't grow the couple of cm I would normally expect.


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## JamieB (8 Jun 2015)

ian_m said:


> It may do, but as only for hour or two makes no odds. Also generally fresh tap water, especially in hard water areas, may be already loaded with CO2 (and O2), which is why you can sometimes get monster plant pearling after water change.


That is very interesting. My MC pearls in my nano tank after a WC, otherwise it only has LC injected in and I wondered why there was O2 bubbles appearing each time!


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## Worshiper (8 Jun 2015)

ian_m said:


> had no power for 3 days after house RCD tripped whilst away due to a supply neutral fault. Tank was less then 16C when I got back, just turned everything back on, tank & filter all fine.


Whoa! 



JamieB said:


> That is very interesting. My MC pearls in my nano tank after a WC, otherwise it only has LC injected in and I wondered why there was O2 bubbles appearing each time!


that's kool! I was always under the impression that LC doesnt cause the plants to pearl due there not being enough of gas saturation in the water so may be that explains why it pearls during a WC.


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## JamieB (8 Jun 2015)

Worshiper said:


> that's kool! I was always under the impression that LC doesnt cause the plants to pearl due there not being enough of gas saturation in the water so may be that explains why it pearls during a WC.



I'm meaning that there must be CO2 in  my tap water as they pearl after a WC


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## Worshiper (8 Jun 2015)

JamieB said:


> I'm meaning that there must be CO2 in my tap water as they pearl after a WC


Just goes to show the quality of water we get in the UK.. good for aquatic plants... bad for all other living organisms.


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## Sk3lly (10 Jun 2015)

JamieB said:


> I'm meaning that there must be CO2 in  my tap water as they pearl after a WC


I think it's more to do with the water being closer to O2 saturation point after a water change. This is sometimes referred to as 'false pearling' 


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## dw1305 (10 Jun 2015)

Hi all,





Sk3lly said:


> I think it's more to do with the water being closer to O2 saturation point after a water change


 I think it is a pressure and temperature effect. When the tap water is in the main it is cool and under pressure. 

Gas solubility decreases as the temperature rises, and increases as the pressure rises. 

When you add the water to the tank it isn't under pressure any longer and it warms, this leads to the dissolved gases coming out of solution.  Because the atmosphere is 70% N2 and 20% O2, and <"neither gas is very soluble"> I would expect that the bubbles are mainly these gases. 

You get the pressure effect when you open a bottle of carbonated drink, the CO2 is held in solution, but as soon as you unscrew the lid, and release the pressure, it out-gases as Co2 bubbles. 

You can see the heat effect when you boil a kettle, as the water warms gas bubbles are evolved, until at boiling the water doesn't contain any dissolved gases at all.

cheers Darrel


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## JamieB (10 Jun 2015)

Very interesting.. Well, shame it's not CO2 as that would be nice for the tank! Still, the more you know..


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## Sk3lly (10 Jun 2015)

dw1305 said:


> Hi all, I think it is a pressure and temperature effect. When the tap water is in the main it is cool and under pressure.
> 
> Gas solubility decreases as the temperature rises, and increases as the pressure rises.
> 
> ...


For my water changes i fill a container on a thursday, it sits there until sunday for my water change. The chlorine has 'gassed' or 'aired' off by this point (i do not know the technical term). I would assume all co2 and o2 would also reach an equilibrium with atmospheric conditions?? Am i correct in thinking this??

Now when i add this water to my tank, i get an increased amount of pearling for that first day. Now is it likely that this water is more rich in o2 than my tank water causing the pearling?? Or do you think as it splashes about during a water change its aerating it more thoroughly?? 

I will add i do get pearling throughout the week. Its just at an increased rate after a water change


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## sciencefiction (10 Jun 2015)

My tap and tank water have a difference of Ph of nearly 1 point, the tap being the lower.  I pretty much think this is due to high CO2 levels. It outgasses very fast with the surface movement and/or airstone.
But one time I sent my fish to the surface. I did a large water change. I normally position the python so it splashes over the surface while it fills the tank but that time it had fallen in the water and I left it. All fish were gasping at the surface by the end of the water change. I dechlorinate with Prime and my tap water contains minor chlorine, no ammonia or nitrites at all. I've done water changes on one tank for weeks without any dechlorinator at all without absolutely no negative effect. So chlorine wasn't the problem. I put a large airstone and within 10 minutes it was back to normal.

Needless to say I now always make sure the incoming water splashes so the gasses come out quicker.


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## dw1305 (10 Jun 2015)

Hi all





Sk3lly said:


> i fill a container on a thursday, it sits there until sunday for my water change. The chlorine has 'gassed' or 'aired' off by this point (i do not know the technical term). I would assume all co2 and o2 would also reach an equilibrium with atmospheric conditions?? Am i correct in thinking this??


 Yes. 





Sk3lly said:


> Now when i add this water to my tank, i get an increased amount of pearling for that first day. Now is it likely that this water is more rich in o2 than my tank water causing the pearling?? Or do you think as it splashes about during a water change its aerating it more thoroughly??


 Possibly, but probably not, either of these factors. It may be a temperature issue (if the water you've added is still cooler then the tank water?) or it maybe a nutrient effect if your water is rich in a limiting element (although presumably not if you use EI).

cheers Darrel


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## dw1305 (10 Jun 2015)

Hi all,





sciencefiction said:


> My tap and tank water have a difference of Ph of nearly 1 point, the tap being the lower. I pretty much think this is due to high CO2 levels. It outgasses very fast with the surface movement and/or airstone.
> But one time I sent my fish to the surface. I did a large water change. I normally position the python so it splashes over the surface while it fills the tank but that time it had fallen in the water and I left it. All fish were gasping at the surface by the end of the water change. I dechlorinate with Prime and my tap water contains minor chlorine, no ammonia or nitrites at all. I've done water changes on one tank for weeks without any dechlorinator at all without absolutely no negative effect. So chlorine wasn't the problem. I put a large airstone and within 10 minutes it was back to normal.


 Sounds like an oxygen or CO2 effect.

As well as CO2 (as H2CO3) being an acid, O2 is a base (so it is really O-H). If the water was either:

de-oxygenated 

or high in CO2 

or both high in CO2 and low in DO.
You would get the effects you describe on both pH and livestock with any of these scenarios.

cheers Darrel


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## ian_m (10 Jun 2015)

Sk3lly said:


> The chlorine has 'gassed' or 'aired' off by this point (i do not know the technical term).


Very dangerous this, you must really always use a dechlorinator. The forums are full of people killing their fish, one guy lost about £600 of fish all in one go after a water change. This issue is chloramine.

Degassing water does not remove chloramine which may be in your water as standard or added to water by the water company in an emergency. I have certainly had chloramine added to my water for a couple of days after we had a water main burst. Water companies used to leaflet people when they did this, warning people not to use the water in their "aquariums & pond" but "but as everyone uses dechlorinator now", they no longer leaflet people.

As you will possibly not know when chloramine is added to your water, you must always add dechlorinator to your water before adding to the tank. If you really really really don't want to dechlorinate test the water with a chlorine test kit first.


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## Sk3lly (10 Jun 2015)

ian_m said:


> Very dangerous this, you must really always use a dechlorinator. The forums are full of people killing their fish, one guy lost about £600 of fish all in one go after a water change. This issue is chloramine.
> 
> Degassing water does not remove chloramine which may be in your water as standard or added to water by the water company in an emergency. I have certainly had chloramine added to my water for a couple of days after we had a water main burst. Water companies used to leaflet people when they did this, warning people not to use the water in their "aquariums & pond" but "but as everyone uses dechlorinator now", they no longer leaflet people.
> 
> As you will possibly not know when chloramine is added to your water, you must always add dechlorinator to your water before adding to the tank. If you really really really don't want to dechlorinate test the water with a chlorine test kit first.


I am aware of the chloramine issue but thank you for the warning. I do run my water through a RO/DI unit. I cut my water with the waste that comes out of the unit. Should i still worry about chloramine or is there no need? I have a bottle if prime in my supplies anyhow 


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## Sk3lly (10 Jun 2015)

Anyway apologies OP i have taken your thread in a different direction. Hopefully some of the info that has been shared has been useful to you.


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## ian_m (10 Jun 2015)

Sk3lly said:


> I do run my water through a RO/DI unit. Should I still worry about chloramine or is there no need?


Which are not guaranteed to process chloramine !!!.

See this thread here about chloramine and RO units and why marine keepers still use Prime with their RO water.
http://www.ukaps.org/forum/threads/filter-to-remove-the-need-for-prime.37173/#post-401160


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## Sk3lly (10 Jun 2015)

ian_m said:


> Which are not guaranteed to process chloramine !!!.
> 
> See this thread here about chloramine and RO units and why marine keepers still use Prime with their RO water.
> http://www.ukaps.org/forum/threads/filter-to-remove-the-need-for-prime.37173/#post-401160


See that i was not aware of. I was under the understanding they did process chloramines. I will from now on add prime to my water change barrel. Thank you Ian for raising this 


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## ian_m (10 Jun 2015)

Sk3lly said:


> I will from now on add prime to my water change barrel


A 100% working RO & DI system will not leave any chlorine or ammonia in the RO output from the incoming waters chlorine or chloramine. However in practice, especially if you don't keep on top of Chlor+ prefilter changing, membrane changing, refreshing/replacing the DI resin and your incoming water has chloramine you can get ammonia (or more rarely chlorine) in the RO water. You can of course just aerate the water for 24hours before use which will remove ammonia and chlorine or test water before use for both ammonia or chlorine or just dose with a small dose of Prime just in case.


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## Julian (10 Jun 2015)

ian_m said:


> Very dangerous this, you must really always use a dechlorinator. The forums are full of people killing their fish, one guy lost about £600 of fish all in one go after a water change. This issue is chloramine.
> 
> Degassing water does not remove chloramine which may be in your water as standard or added to water by the water company in an emergency. I have certainly had chloramine added to my water for a couple of days after we had a water main burst. Water companies used to leaflet people when they did this, warning people not to use the water in their "aquariums & pond" but "but as everyone uses dechlorinator now", they no longer leaflet people.
> 
> As you will possibly not know when chloramine is added to your water, you must always add dechlorinator to your water before adding to the tank. If you really really really don't want to dechlorinate test the water with a chlorine test kit first.



I know we all hate test kits on this forum, but are there any cheap test-strips that test for chlorine+chloramine? I do 2 50% water changes a week, I hate paying for new dechlorinator!

Another thing, if my tank is 80L and I change 50% of the water, do I only need to add enough dechlorinator to treat 40L?


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## dw1305 (10 Jun 2015)

Hi all, 





ian_m said:


> The forums are full of people killing their fish, one guy lost about £600 of fish all in one go after a water change. This issue is chloramine.


 "Emergency chloramine treatment" is an <"ongoing issue">.  I use rain-water, but If I was forced to use tap water I'd by "Pond Prime" as a dechlorinator.

The chloramine compounds themselves are toxic, according to the ever erudite <"Skeptical Aquarist - Dealing with chlorine and chloramine">.

cheers Darrel


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## parotet (10 Jun 2015)

Seachem Prime seems to be one of the few that expressly states to get rid of chloramines... and to be honest the amount to be added in each water change is ridiculous compared to other dechlorinators (at least for me, with just 100 liters of total volume with all my tanks). Now I'm using also rain water mixed with tap water (75%-25%), lately I forgot to add the dechlorinator  but not when there are meteorological events to be worried about. I live in the Mediterranean coast and sometimes (i.e. during the very dry summers or after some very heavy rainfalls in autumn) the water quality decreases and the risk of having chloramines is higher. 

Jordi


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## ian_m (10 Jun 2015)

Julian said:


> but are there any cheap test-strips that test for chlorine+chloramine?


Yes, swimming pool test strips work very well, apparently and are cheap, though need to ensure correct type to cope with total chlorine and not just free chlorine.



Julian said:


> do I only need to add enough dechlorinator to treat 40L


Only add Prime for the volume of fresh water if it is being put in a bucket first for 40litres you will need 1ml of Prime.

If you are adding your fresh water to your tank, you add the Prime dose for your tank volume so 2ml.

Dose using a syringe or pipette.

Prime costs say £18 for 500ml so that's 3.6p per ml. Money well spent.


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## Julian (10 Jun 2015)

ian_m said:


> Yes, swimming pool test strips work very well, apparently and are cheap, though need to ensure correct type to cope with total chlorine and not just free chlorine.
> 
> Only add Prime for the volume of fresh water if it is being put in a bucket first for 40litres you will need 1ml of Prime.
> 
> ...




Wow, that's so much more cost effective than Tetra Aquasafe... Thanks!


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## ian_m (10 Jun 2015)

Julian said:


> Tetra Aquasafe


Remember also the Aquasafe can't be used if you have Purigen in you tank/filter. It clogs the pores and stops it being able to regenerate.



Julian said:


> Wow, that's so much more cost effective


But Prime is even more expensive compared to sodium thiosulphate. You can get 1KG for £8 on Ebay and you will require 0.4gr  (0.24pence worth) to dechlorinate your 40l. Thiosulphate won't remove ammonia though, you need Prime or AmQuel for that.


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## sciencefiction (12 Jun 2015)

Wrong thread


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## Worshiper (16 Jun 2015)

Sk3lly said:


> Anyway apologies OP i have taken your thread in a different direction. Hopefully some of the info that has been shared has been useful to you.


that's no bother  I have learnt a lot more than I expected.   It's all good though.. I need all this as I consider myself a newbie.


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## Christos Ioannou (16 Jun 2015)

ian_m said:


> Remember also the Aquasafe can't be used if you have Purigen in you tank/filter. It clogs the pores and stops it being able to regenerate.


Very interesting this! Which ingredient causes this? Need to check my dechlorinator asap!


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## ian_m (16 Jun 2015)

Christos Ioannou said:


> Which ingredient causes this?


It's any water conditioner that contains a slime coat will render Purigen useless (un rechargeable).

At the bottom of the page here.
http://www.seachem.com/Products/product_pages/Purigen.html

Here is a big list of water conditioners and if they contain slime coat.
http://www.thetropicaltank.co.uk/rev-cond.htm

Slime coat is rather a moot point, as the amount added to the water is going to make b*gger all difference to the fish and people have been using sodium thiosulphate and other non slime coat conditioners for years and have never seen fish issues. More of a marketing point I feel.


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## Sk3lly (16 Jun 2015)

ian_m said:


> It's any water conditioner that contains a slime coat will render Purigen useless (un rechargeable).
> 
> At the bottom of the page here.
> http://www.seachem.com/Products/product_pages/Purigen.html
> ...


So to understand this correctly... The use of seachem prime renders the purigen effectively useless?


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## ian_m (16 Jun 2015)

No Prime is ok. It even states use Prime in Purigen instructions


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## Christos Ioannou (16 Jun 2015)

But Prime is listed as Y for slime coat


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## xim (16 Jun 2015)

Christos Ioannou said:


> But Prime is listed as Y for slime coat



Only SOME slime coat products are incompatible.
http://www.seachem.com/support/FAQs/Purigen.html
They know what they are selling and not selling. I'm just saying.


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## Sk3lly (16 Jun 2015)

xim said:


> Only SOME slime coat products are incompatible.
> http://www.seachem.com/support/FAQs/Purigen.html
> They know what they are selling and not selling. I'm just saying.


Yea i was just getting a little confused as per the table Ian posted. Makes sense now though. 

Thankyou Ian for the table


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