# Most efficient water change method for large tank



## idris (14 Jan 2017)

My tank is 250L and 2ft deep.
For water changes it's always been "easiest" to ...

pump water from the tank into a 25L canister (I have a small external pump for this)

drag the canister outside and empty it
fill the canister with tap water
add dechlorinator etc, 

heat the canister to match the tank.
pump water from the caister back into the tank.
Even doing a 10% water change takes best part of an hour and has always been a bit of a PITA. If I want to do 20%, even more so. Consequently I procrastinate and don't do it as regularly as I should ... with obvious consequences.
Finding a more efficient way to do water changes will hopefully help me be a more diligent aquarist and having a healthier aquarium.

I've looked at Pythons (branded and DIY) but I'm wary of them for two main reasons:

You have to add chlorinated water directly to the tank. 

It's harder to ensure you get the tap water at the right temperature, 
As I've had a couple of occasions where I've wiped out all the fish in the tank when doing a water change without ever been able to say for certain why, I'm reluctant to run tap water straight into the tank.

Any suggestions on a more efficient way to do water changes?


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## Aqua360 (14 Jan 2017)

Drip system


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## idris (14 Jan 2017)

Do you mean a system that is filled constantly, but very slowly, from the mains water, and then overflows into a drain?
If so, nice idea, but there's no easy way to route mains water to the tank on a permanent basis.


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## jolt100 (14 Jan 2017)

Hi, I have a large water butt which I fill 24 hrs before a change,  it holds around 200 litres and my house tank is 350 so enough for a 50% change. It's in my fish shed which is insulated and kept at 20C so gets to near enough tank temperature. I don't add any dechlorinator.
I use 1" hose with a foam prefilter to syphon to the drain, this takes 15 mins max for 150+ litres. While this is draining I clean the prefilter on my filter and circulation pump. I then connect the pipe to a pump in the water butt and fill the tank, another 15 mins.
If I don't do any other trimming the total time including clearing up is 40minutes. Needs a good size pond pump.
If you have somewhere to keep the butt and hose you can pre-fill with hot/cold water and add dechlorinator then pump.  
Cheers 
John


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## foxfish (14 Jan 2017)

idris said:


> Do you mean a system that is filled constantly, but very slowly, from the mains water, and then overflows into a drain?
> If so, nice idea, but there's no easy way to route mains water to the tank on a permanent basis.


Obviously I don't know the lay out of your house but, I have my tanks plumed into the mains water supply  via 6mm RO tube.
The white 6mm pipe is quite easy to hide, in fact mine goes up from the kitchen sink (very easy DIY fittings available) into the loft and back down into my lounge tank. This involved two 6mm holes in the ceiling but honestly it would only take a dab of filler to hide them if we ever sold the house.
In my case I have a mini RO ball valve attached to the rim of the tank so all I have do to perform a water change is run some 6mm air line & start a syphon into the sink & let it auto top up the tank.


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## idris (14 Jan 2017)

Sadly adding a mains feed would involve either lifting most of the kitchen floor, taking down the ceiling or  going through an external wall twice. 
And a water butt would put give me a similar situation to which I already have, as I have indoor space and would still have to decant it and heat it.


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## KipperSarnie (14 Jan 2017)

I'm working on a DIY water change system at the moment as like you with 6 tanks smallest 200lt water changes take forever.  
I will post a video when I'm happy with it.
I have now all the materials & so far cost about £20 for all 5 separate tanks & no tank drilling required, there are a lot more to syphons than just suck & let it flow!


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## Adam Chambers (14 Jan 2017)

At the moment I drain my tank direct out the window that is 2ft from the aquarium. Then I run the hose on low and refill from there as I have no fish. The only difference I will have once I get fish is that I will be adding some Prime to the tank as it is filling during water changes. I would really like to go external from outside tap to run into a water butt and feed from that but the effort to do so at this time I don't think I will be.


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## sciencefiction (14 Jan 2017)

idris said:


> Finding a more efficient way to do water changes will hopefully help me be a more diligent aquarist and having a healthier aquarium.



The most efficient way is always the easiest way for the same reasons you stated....otherwise one starts dreading it.

....I know you mentioned you wiped your tanks twice by doing a water change..which must have been a horrific experience....but.If you hadn't changed much water very often in the first place, your tank and tap water in time would get million years apart...Doing the odd larger water change can shock the fish in this case ..or your water company had the odd large dump of chlorine/chloramines and your dechlorinator wasn't up to it. I've used a python for years, the day after I upgraded to larger tanks after it took me half the day to fill one tank up with buckets  I have never had a problem doing large water changes straight from the tap. They fish are active and happy even while I do a water change. Varying the temperature up to 2-3 degrees is also just fine. I use my hand to roughly make sure its not too cold or too warm.  Use quality dechlorinator like Prime. You can buy it cheaply online and it is very concentrated....lasts a long time. I normally put 1.5-2 times the recommended dose(for the tank size) just before I start filling...

If you think of it, putting dechlor in a bucket and then pouring the water is just one extra step. Pouring the full dose of dechlor for the tank directly in the tank is the same thing. Prime is active for 24-48hrs...It will be effective the moment you start pouring tap water for longer than it takes to fill the tank...unless it takes you two days


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## idris (14 Jan 2017)

Ok. +1 for pythons. 
Though I'd disagree about adding decjlorinator to a bucket - considering I leave that to warm up with a spare aquarium heater, I've been working on the theory that that has a good chance to work before it's added to the tank.


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## Daveslaney (14 Jan 2017)

I was always of the impresion declorinators neutralise the nasties in the tap water instantly?


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## idris (15 Jan 2017)

Entirely possible. I don't know.But in a 250L tank there is the possibility that the distribution of chlorine etc and dechlorinator don't match. 
A couple of times I've had a lot of dust algae to scrape off the glass. Once this is in the water it can take 10-15min to get filtered out of the water, and it isn't distributed around the tank evenly. So if dechlorinator and untreated water are getting mixed in the tank, there's a significant chance fish can be "chlorinated" for more time than I'm comfortable with. I mix them in a smaller canister, especially if I put the dechlorinator in first, the mix will be much quicker and the fish won't be effected.


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## Costa (15 Jan 2017)

I feel the OP. I've got a 800L tank and water changes are a b*tch. I should ideally be preparing the water in a large plastic tank, but this isn't possible for that kind of volume. So what I do at the moment is that I do small water changes (like 25% weekly or every 10 days) directly from the tap and add dechlorinator in small doses as the water goes into the tank, taking advantage of the flow that the water coming in creates, and I am guessing that this flow distributes the dechlorinator evenly.

The dechlorinator is one thing though, my main concern is the temperature; the new water is usually >5'C lower than the tank water (in the winter it's more like 15'C lower, maybe more). The only solution to this that I came up with is the very slow introduction of the new water, it takes me about 3 hours to do the water change.

Any ideas very welcome. Looking forward to KipperSarnie's video.

Edit:

When using water directly from the tap, I believe that the key is in the frequency of the changes. If I would be changing the water every two or three months, a 50% water change using tap water would be guaranteed to wipe the entire tank.


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## Costa (15 Jan 2017)

sciencefiction said:


> If you hadn't changed much water very often in the first place, your tank and tap water in time would get million years apart...Doing the odd larger water change can shock the fish in this case ..or your water company had the odd large dump of chlorine/chloramines and your dechlorinator wasn't up to it. I've used a python for years, the day after I upgraded to larger tanks after it took me half the day to fill one tank up with buckets  I have never had a problem doing large water changes straight from the tap. They fish are active and happy even while I do a water change. Varying the temperature up to 2-3 degrees is also just fine. I use my hand to roughly make sure its not too cold or too warm. Use quality dechlorinator like Prime. You can buy it cheaply online and it is very concentrated....lasts a long time. I normally put 1.5-2 times the recommended dose(for the tank size) just before I start filling...
> 
> If you think of it, putting dechlor in a bucket and then pouring the water is just one extra step. Pouring the full dose of dechlor for the tank directly in the tank is the same thing. Prime is active for 24-48hrs...It will be effective the moment you start pouring tap water for longer than it takes to fill the tank...unless it takes you two days



That. I'm with you 100%.


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## sciencefiction (15 Jan 2017)

idris said:


> A couple of times I've had a lot of dust algae to scrape off the glass. Once this is in the water it can take 10-15min to get filtered out of the water, and it isn't distributed around the tank evenly.



Dechlorinator acts by chemical reactions...not by flow and distribution.  The effect is  immediate...What you are afraid of is fear itself. All I would be worried about is putting enough dechlorinator to neutralize the amount of chlorine your water company adds normally. That's why I do a double dose just in case they've dumped more than usual..However, if that's the case...mixing in a bucket can't save you either...
If you age your water, it may help some more against a higher dump by the water company(unless they dose chloramines which needs dechlorinator) but the containers where water is aged will start going through nitrification in a matter of days too(2-3 days max), and there's a chance you add water with ammonia and/or nitrite in your tank...if you age the water for too long....a week could be too long.


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## sciencefiction (15 Jan 2017)

@Costa 

Is it just a cold tap you can connect the python to? I use both hot and cold tap,. I match the water closely enough. Temperature is not an issue...


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## ian_m (15 Jan 2017)

This is what I use, to change 100l odd of water. Means quick tank vacuum, quick trim and refill all done in under an hour.
https://www.ukaps.org/forum/threads/water-change-heater-project.25877/

I used the above and not heating the water as some people "state the fact" that I will kill all my fish. I can report tank water dropped to 18'C, fish not bothered in fact seemed to like swimming in and out of the incoming water flow !!!.

You really must use dechlorinator to remove chlorine and chloramine from the tap water. Some dechlorinators will remove heavy metals, but in UK heavy metals are in such low levels not a problem for fish.

The chlorine/chloramine has two issues once in the tank, it will irritate fishes gills and will kill bacteria. Generally this will not kill fish as chlorine/chloramine will react with organics in the tank and not be round long enough to be fatal to fish. This is why some people get away water changing with tap water only, that is until the much stronger chloramine is added to the water and they kill their tank !!!

However chlorine/chloramine it will kill bacteria in your filter pretty effectively, so if you dose the tank with dechlorinator and then add tap water, make sure your filter is off. If you kill your filter bacteria with tap water it will start rotting and a day or two after adding tap water will leech lethal levels of ammonia into your water, promptly killing your fish. This is why people get their fish deaths a day or two after doing the undechlorinated water change.

I did have some links where someone lost £650 of fish (in many tanks) shortly after water changes as he thought bubbling air though a storage tank of water would dechlorinate it effectively. Unfortunately the water company started dosing chloramine after a burst water main and possible water contamination. Again a few pence of dechlorinator would have saved the fish (and filtration). Testing the water after the event revealed ammonia levels off the scale (5ppm) from both rotting filters and chloramine breakdown products.


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## sciencefiction (15 Jan 2017)

Ian_m...you're are talking of a scenario where one does not add dechlorinator in the water...I agree, you must use a dechlorinator and it must be at a dose enough to counteract whatever the water company doses. I do have my filters off during a water change but in my small tanks the purpose of that is defeated because I've got internal filters mostly...not an issue either pouring tap water directly and dosing the tank with dechlor directly..


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## Daveslaney (15 Jan 2017)

The reason i was asking is because i add the declorinater directly to the tank. I have been down the route of using brewing buckets to airate and heat the watet and as the OP says it is a pain and makes you dread water change days to be honest.
Now i just syphon the water fron the tank. Add declorinater direct to the tank and fill with the hose. Alot easier.
Sure i do get a slight temp drop of 2 to 3 deg but have seen no problems with this. Temp is the main reason i do two 25% water changes a week instead of one large  50%.


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## sciencefiction (15 Jan 2017)

Water changes are preferable to be on the larger side at once to actually have an effect because concentrations of harmful substances rise all the time...But lets be unreasonabe and assume that the new water is pure and the concentration of whatever you're trying to remove from the tank never goes up...

*Then for example, if you want to bring 40 ppm nitrates to a 5 ppm level*

Daily water change @

70% - takes 2 water changes
50% - takes 3 water changes
40% - takes 4 water changes
25% - takes 7 water changes
20% - takes 9 water changes
10% - takes 19 water changes

*To reduce 1ppm ammonia to 0.0X ppm where X is a value below 5* ( the lower you want to bring more toxic substances down, the more water changes it takes)

Daily water change @

70% - takes 3 water changes
50% - takes 4 water changes
40% - takes 6 water changes
25% - takes 14 water changes
20% - takes 9 water changes
10% - takes 29 water changes

People tend to do one weekly water change....So if you are a low volume water changer...e.g. 10-20% weeky, it will take you a quarter to half a year to remove 1ppm ammonia from your system....You might as well not do water changes... The best thing is to adopt a method where large volumes of water changes are done at once....If you have a python, you just sit and watch with a cup of coffee....maybe taking videos...I actually put a bit of food at the same time and watch the fuss...Fish forget someone is fiddling with the tank...


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## themodernchap (15 Jan 2017)

I think the best waterchange system is the Reefloat. Not sure if I'm allowed to link to their site but it's very well thought of in the UK reef scene. You fill it with fresh water, link it into your system and it slowly circulates the fresh water into your system. Then you disconnect it and drain it. They reckon that you waste about 5% of the fresh water but I think it is well worth it for the convenience. It's fully automated you just set it and go do something else, it beeps when full mixing has been achieved. It can also premix salt water for reefs or I suppose it could re mineralise RO for planted tanks. UK made and excellent customer service too.


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## simon Coram (15 Jan 2017)

I drain out my tank about 25ltrs into a bucket, in the garage i have a 25 water container heating up to temp.
waste water goes on the back garden after I've checked it for little baby shrimp.
I put the ironing board up so its at the same height as the tank, put the clean water container on it, take the lid off and syphon it back into the tank.

The first time i did it the wife got excited it was going to do the ironing.


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## idris (15 Jan 2017)

Is the Reefoat anything more than a bucket with a pump and a timer?


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## HiNtZ (27 Jan 2017)

I siphon 100% of my tanks, both directions - no pumps needed. I'm fortunate to have a high cabinet next to 3 of them, a windowsill next to the other, and downstairs a make shift platform in the form of a stepladder to fill them all up.

As for heating, I tend to run a scalding bath and leave the 25L containers full of the cold water in them until it neutralises. But, I'm going to get a little 12v pump, some aluminum tube and heat my containers using my wood burner to save money on the gas. Obviously in the summer water temp is a non issue.

Question about drip feeding a tank with mains - how to you dechlorinate??


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## ian_m (27 Jan 2017)

HiNtZ said:


> Question about drip feeding a tank with mains - how to you dechlorinate??


If drip feeding slow enough there is some argument that dechlorination is not necessary as any chlorine/chloramine will be quickly reacted away by tank organics/salts. Possibly OK depending on amount of water added.

Normally, if doing drip filling properly, you would automatically fill water butt with mains water, automatically dose dechlorinator then drip feed, using a peristaltic pump from the butt to the tank. Has the advantage that mains pressure water is kept away from the tank and you can use multiple valves on the mains water (electric and a float valve) to provide redundancy against flooding. Just needs a water butt, float sensor at bottom to detect it is empty, float sensor and ball float valve at top to turn water off when full, a relay to hold water fill on to fill butt once empty and a timed relay to dose dechlorinator.

You will also need an overflow (+backup safety overflow) to drain water excess water as you add more water. This type of thing is very common in the marine world, made more complicated as generally use RO water and have to add salt to water as well.


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## idris (27 Jan 2017)

ian_m said:


> … peristaltic pump … multiple valves … water butt, float sensor at bottom … float sensor and ball float valve at top … relay to hold water fill on … timed relay to dose dechlorinator … overflow (+backup safety overflow) …


 ****** on a bike! I think it would be easier to do water changes with a chipped mug than set all that lot up.


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## ian_m (27 Jan 2017)

idris said:


> ****** on a bike! I think it would be easier to do water changes with a chipped mug than set all that lot up.


But some people like to use these type things. Once built and setup just does water changes without any intervention. No use of chipped mugs, no buckets of water going through the house water changes all done from comfort of your arm chair.

Not to sure how you cope with all the debris that accumulates in a high tech tank. Below is the detritus I seem to vacuum out weekly from my 180l tank.


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## st.john (9 Feb 2017)

syphoned hosepipe into the bath for me! then mixer tap to refill while dosing with aquasafe..


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## xim (9 Feb 2017)

I also don't feel comfortable about applying dechlorinator directly to the tank. So this is the method I use. Yes, I still have to lift the 12l bucket but that's OK. I also use the same long hose (about 10 metres perhaps) to vacuum and drain the tank to the backyard. My tank is 340 litres, the water change is 66% weekly. The draining and filling process takes about 45 min.


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## Andrew Butler (14 Jul 2017)

If you have good circulation with decent filtration you still have all this settle?
Can you strike a balance of plants and fish that don't need the substrate/bottom vacuuming?



ian_m said:


> But some people like to use these type things. Once built and setup just does water changes without any intervention. No use of chipped mugs, no buckets of water going through the house water changes all done from comfort of your arm chair.
> 
> Not to sure how you cope with all the debris that accumulates in a high tech tank. Below is the detritus I seem to vacuum out weekly from my 180l tank.
> 
> View attachment 102382


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