# Water Changes on Larger Tanks



## zfarsh (Apr 7, 2011)

Hi there,

I have a new 75 gallon tank. It will be planted with play sand substrate, and have Fancy Goldfish / bristlenose Plecos, Eheim 2217 canister fiter, and and Aquaclear back-up filter. That said, i want to know how people do water changes on such large aquariusm, say i need to do a weekly 25 - 50 % change (depending on final load of fish)? Honnestly, i wanted to use a hose and tap water, and only after to add the Prime to the aquarium, but i dont know if that would kill the good bacteries even if the fitlers are off. Otherwise, how do you handle such a large change? Thanks in advance.


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## aeri (Sep 9, 2007)

i just use a python hose to drain and put water back straight from the tap. no need to turn off the filter unless the water level is going below the intake


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## Marowana (Jul 28, 2009)

i do 25-40% water change weekly with fresh tapwater and prime. the only difference is i add prime before i top off. no problem so far...


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## TBemba (Jan 11, 2010)

I agree with the others ^^

I have been using a python for years and doing it the same way as the people above.

it makes it so much easier to clean the substrate and remove and replace water it makes quick and easy to do large water changes so you will do them more often and it will only benefit the fish.

I change 40% - 50% every week and clean filters every month.


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## zfarsh (Apr 7, 2011)

ok, thanks guys about the Python idea, i saw it in the forums, but didnt know the difference between that and one i have to drain the water with gravity.... But i read there is also a Aquaeon Water Changer, and it is cheaper / better, so going to get that. Honnestly, this could really revolutionize the way i do things. I think it will make it SOOO MUCH easier based on what i see in youtube. No more lifting water pales.


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## BillD (Jun 5, 2006)

If you can drain via gravity, you don't need a Python. They are too slow for me, since I will often fill one tank while draining another. My fill line has a gooseneck on the end, terminating in a tee, which allows for much faster fill ups.


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## vrb th hrb (Feb 20, 2010)

when possible I change 50% twice a week, wring out the sponge on the AC70 once a week. clean the canisters about once a month. it doesnt effect the bene bacteria in the filters

is it overkill, probably. but I have alot of big messy plecos in a 75 gallon. and since i've been doing this I've noticed them growing alot faster.


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## splur (May 11, 2011)

50%?! Wow, I'm totally underdoing my duty, I do like... 10% at max? The first 1.5 inches of the tank... make me look like a neglectful owner.


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## Lee_D (Jun 11, 2010)

Actually, a 50% water change scares the crap out of me. I always thought the most important part of fish keeping was maintaining stability in the tank. Replacing half the water in the tank with straight tap water seems far from stable to me. You have very little control over the water temperature and there is no opportunity to remove the chlorine. Adding prime after the fact (or before for that matter) still gives plenty of time for the chlorine to react with the fishes gills. Me? It may be inconvenient but I'm going to stick with aging my water overnight and use a bucket to add / remove my water change water.

Lee


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## vrb th hrb (Feb 20, 2010)

splur said:


> 50%?! Wow, I'm totally underdoing my duty, I do like... 10% at max? The first 1.5 inches of the tank... make me look like a neglectful owner.


not at all, as I said I'm pretty sure it's overkill, but it's my tank and in turn my choice. I feed fresh veggies at least twice a week so my substrate can get pretty dirty at times. Water goes back in aerated at 76f while I add prime with my heater and powerhead running.

While I understand there is no chlorine in these fishes natural environment, they also are river dwellers and in turn have fresh water running by them all the time. I used to have four buckets of water hiding under my fish stand, now that I live with my gf I cant really do that as the cats will drink from them/fill them with hair.


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## Marowana (Jul 28, 2009)

Lee_D said:


> Actually, a 50% water change scares the crap out of me. I always thought the most important part of fish keeping was maintaining stability in the tank. Replacing half the water in the tank with straight tap water seems far from stable to me. You have very little control over the water temperature and there is no opportunity to remove the chlorine. Adding prime after the fact (or before for that matter) still gives plenty of time for the chlorine to react with the fishes gills. Me? It may be inconvenient but I'm going to stick with aging my water overnight and use a bucket to add / remove my water change water.
> 
> Lee


storing water overnight will not remove chloramine. temperature can be adjusted at the faucet.


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## BillD (Jun 5, 2006)

Lee_D said:


> Actually, a 50% water change scares the crap out of me. I always thought the most important part of fish keeping was maintaining stability in the tank. Replacing half the water in the tank with straight tap water seems far from stable to me. You have very little control over the water temperature and there is no opportunity to remove the chlorine. Adding prime after the fact (or before for that matter) still gives plenty of time for the chlorine to react with the fishes gills. Me? It may be inconvenient but I'm going to stick with aging my water overnight and use a bucket to add / remove my water change water.
> 
> Lee


Scared for no reason. Large water changes done regularly are more likely to maintain stability than small changes, either frequently or infrequently. As well, 50% is not a large change. A dechlor will react instantly with chlorine on contact so there isn't a lot of time for the chlorine to react with the fishes gills. Aging water is fine if you have one tank, but it becomes problematic when you have several. I guess it depends how much work you are willing to do. For me, aging the water for 20 feet works and is quick.


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