# water change in large aquariums (200 gallon)



## vincel892 (May 23, 2012)

I may have posted this question in other forums before but just wanted to get other opinions regarding water changes in large aquariums. I have a 200 gallon and was using an automatic "drip system" to change the water. I calculated that it would take ~13 hours (taking into account mixing of old and new water) for a 50% water change. The issue I have is that the temperature drops from 25C (what its normally at) to 20C. When I only had plants, I didnt think it was that big of a deal. But now that there are neon tetras in the tank, they have developed some sort of fungus which i feel is probably due to the drastic change in temperatures every time I do a water change (weekly). I am also planning to purchase either angelfish or german blue rams in the future and figured I should deal with this problem before committing to more expensive fish. 
My alternative to doing water changes this way would be to use a python and just change it manually. It would involve more manual labour but its doable. 

Any ideas/suggestions?


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## kolegrundy92 (May 9, 2016)

Do smaller water changes! My suggestion. A 200 gallon planted tank should not need 50% change a week...maybe leave it another week and check your levels again they may balance out.

Sent from my SGH-I337M using Tapatalk


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## TBemba (Jan 11, 2010)

Could always get a 50 gallon barrel and fill it up treat it and put a heater in the barrel an then use it to change your water. 

Back in the old days, I had a python to fill a 125 I had and would just empty roughly 25% then add the water straight back from the tap mixed to an lukewarm temperature and a squirt of Prime and never had issues.


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## vincel892 (May 23, 2012)

kolegrundy92 said:


> Do smaller water changes! My suggestion. A 200 gallon planted tank should not need 50% change a week...maybe leave it another week and check your levels again they may balance out.
> 
> Sent from my SGH-I337M using Tapatalk


Thanks for the input. The reason I do a 50% change is beceause I dose EI. I am following what I have read elsewhere. However, I am planning to go on a leaner dosing regimen like PPS-pro and possibly do a smaller change every week.


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## vincel892 (May 23, 2012)

TBemba said:


> Could always get a 50 gallon barrel and fill it up treat it and put a heater in the barrel an then use it to change your water.
> 
> Back in the old days, I had a python to fill a 125 I had and would just empty roughly 25% then add the water straight back from the tap mixed to an lukewarm temperature and a squirt of Prime and never had issues.


Was thinking of going with the python. seems like the most efficient method


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## Dis (Apr 16, 2010)

I use a python and a hose with a a pvc tube. I drain my 220 with both of them and refill with the python. Draining with just one hose is really slow.


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## infolific (Apr 10, 2016)

I have no experience with automated drip systems, but the first thing that popped into my head was to use a long hose between the source of the water and the tank. Even if the distance between the two isn't great, a long hose will give the water a chance to warm up to room temperature before it gets into the tank.

Or a variation of that idea, wrap the hose around something that is warm. For example, if you've got a solenoid as part of your CO2 setup you could use the heat to warm up the water a bit. 

As for EI, there's nothing that says you can't reduce the amounts. EI is just a starting point. If you scale back and see the same plant growth, you could reduce the frequency of water changes.


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## cb1021 (Sep 21, 2009)

Can't you change the settings on your tap for the drip feed?


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## vincel892 (May 23, 2012)

cb1021 said:


> Can't you change the settings on your tap for the drip feed?


I've thought of that but the problem is the cold and hot water taps are separate. I would need to join them somehow before it enters the main line into the tank


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## cb1021 (Sep 21, 2009)

That seems like a good solution. Automatic WC rocks.


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## Dis (Apr 16, 2010)

5 degrees shouldn't be too bad. You could install another heater to help bring the temp up faster. Maybe there is another issue with the tetras. I often go down 5 degrees, but usually 80 to 75


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## default (May 28, 2011)

Is there any way to turn down the drip rate? By extending the amount of time and decreasing the amount added?

Also, as mentioned by Infolific, technically it's not mandatory to do 50% water changes, only recommended. Another approach to this if you don't mind investing a little more time and *only* if you can turn down the amount added - or else I'd recommend turning it down and just letting it change at a slower rate - the other approach is to do 25% water changes twice a week instead of one 50%.
Simply dose half of your fertilization regime after each WC, it wouldn't be a traditional EI method, but I found a little under fertilization (It's EI, even by half you're probably going to have a surplus ) with more frequent WC is quite efficient and you'll get great growth from it.


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## vincel892 (May 23, 2012)

cb1021 said:


> That seems like a good solution. Automatic WC rocks.


Is this how you do it with your big tank?


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## vincel892 (May 23, 2012)

Dis said:


> 5 degrees shouldn't be too bad. You could install another heater to help bring the temp up faster. Maybe there is another issue with the tetras. I often go down 5 degrees, but usually 80 to 75


In the winter with both my 300w heaters turned to max, the highest temp it goes is 25 C. My heaters are in the sump so I'm thinking of insulating that with some foam board and getting a third heater that goes in the tank itself.


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## vincel892 (May 23, 2012)

default said:


> Is there any way to turn down the drip rate? By extending the amount of time and decreasing the amount added?
> 
> Also, as mentioned by Infolific, technically it's not mandatory to do 50% water changes, only recommended. Another approach to this if you don't mind investing a little more time and *only* if you can turn down the amount added - or else I'd recommend turning it down and just letting it change at a slower rate - the other approach is to do 25% water changes twice a week instead of one 50%.
> Simply dose half of your fertilization regime after each WC, it wouldn't be a traditional EI method, but I found a little under fertilization (It's EI, even by half you're probably going to have a surplus ) with more frequent WC is quite efficient and you'll get great growth from it.


I think I will start tapering my dosing and see how that goes. I think slower growth would be better as well since I have less time on my hands now. 
In regards to the temperature , I think I found a way to connect the cold and hot water tap so that I can actually adjust the temp of the water being added. Don't know why I never thought about this before.


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## harveysburger (Feb 16, 2009)

+1 for the barrel approach. I have 54g barrel which I refill after each water change. The water gets preheated to what I need. Then I use water pumps to empty the tank and fill it back from the barrel. 

I tried with a python before but Iver long distances like 50' the water flow is way too slow, ends up taking forever to do 50+ gallons. With cheap 'strong but noisy' pumps the job gets done way faster


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