Water Changes

[justin neilson]

How Often Should I Change The Water In My Tank? I Have Heard
Different Answers. Pet Store Clerk Told Me He Water Changes 20%
Of Water Every Two Weeks?

[Incredulous_Ed]

10-20% a week is the norm, but if you can, do 50% percent every week

[Glasstapper]

um, well, what kind of fish do you have and what size tank, and what kind of filtration?

See, if you have a messy fish, like say a goldfish, in a 10 gallon tank with only a HOB filter rated for 10 gallons, I'd say you would need to change out about half the water weekly.

However, if you have just some really small fish, like guppies, tetras, platies all in a 30 gallon tank with double filtration, I'd say only 20% every 10 days to two weeks.

So what are we talking here?

[Lady Hobbs]

Big controversary here on water changes. It depends on how large your tank is, what kind of fish and how much stock you have.

I do 40% every week.

[Nautilus29]

It usually depends for me, I just changes out as much as it takes me to clean out the gravel with my gravel cleaner. Which usually ends up being about 30 to 40% in my 10g.

I have yet to do a water change on my 55g becuase it just cycled. im going to this weekend.

[jeffs99dime]

personally, i like larger water changes one a week at about 50-60%.

[cocoa_pleco]

I like about 30% once a week

[Fishguy2727]

Weekly is ideal and the MINIMUM amount will vary depending on previously mentioned things. More is better, even if it means breaking it up to twice a week. Nitrates should not go above 20ppm tops.

[Scuba Guy]

And now for a completely different answer -

How about not at all. No water changes. In fact - just add water to cover for evaporation.

No way - you say.....

My father NEVER changed the water. He believed in a balanced 'eco-system' approach with plants to take up the wastes and fish to provide the wastes.

As long as he was cutting out the plants (water sprite mostly), he felt the tank would be healthy.....

and sure enough - since I grew up there, his tanks thrived. Breeding pairs of angels on and off. These fished lived years with broods raised with the parents...in a tank with NO WATER changes. And no CO2 either...just plenty of light...plenty of catfish and pleco's and Angels. This was a 55 gallon tank.

It did great - went acid over time (because of NO WATER CHANGES) which the angels just seemed to thrive on.

It worked for him.

I tried it here in Houston. Dead fish.

This sucks.

[Incredulous_Ed]

wow, that is really cool. the angels and corys both do well in acidic water, so that might explain something

[cocoa_pleco]

yeah. My doctors 33g with 15 blood parrots (dont ask) is never vacummed, and theyre ok. What if i dont change any water

[jeffs99dime]

yeah. My doctors 33g with 15 blood parrots (dont ask) is never vacummed, and theyre ok. What if i dont change any water

i wouldn't recommend it

[AuroraAustralis]

I wouldn't recommend it either. An aquarium is a closed system and to keep it in a healthy state with no water changes and only water added is possible but is like walking on a knife edge... dangerously risky. To pull that off you would need to accomplish a nearly impossible balance. The very precise, delicate balance that nature provides is all but impossible to replicate in an aquarium with no waterchanges and getting it close is just not close enough. Sooner or later any excess of nitrates, phosphates etc not being used up by the plants, will with no water changes build up until it eventually causes problems. I do weekly waterchanges of 30-50% depending on how much time I take gravel cleaning & I do daily 10% changes when raising fry.

[Lady Hobbs]

yeah. My doctors 33g with 15 blood parrots (dont ask) is never vacummed, and theyre ok. What if i dont change any water

How can 15 blood parrots fit in a 33 gallon?

[Cichlid_Man]

All great responses here.
I personally do 20% water changes twice a week.

Depending on what fish you have and what PH is required, you can change as much water as you want.

I have to break my changes up into two because there is a huge difference in the tap water and what my cichlids require.

If you have 7.0 tap and the fish require 7.0 or a bit higher, you can virtually change 90% of your water.

75% would be perfect each week.

[Fishguy2727]

That tank that went acidic because of no water changes shows it was not balanced. It is conceivable to have a balanced tank but not likely, and not without experience (or extreme luck). It requires a huge plant load, very few fish, and even then usually won't work. No water changes is not really an option. And a 33 with a ton of parrots with no water changes, out of the question. It needs its water changes too.

[Severus]

I have been doing 40% weekly and it has been working great.

[Sasquatch]

I wouldn't recommend it either. An aquarium is a closed system and to keep it in a healthy state with no water changes and only water added is possible but is like walking on a knife edge... dangerously risky. To pull that off you would need to accomplish a nearly impossible balance. The very precise, delicate balance that nature provides is all but impossible to replicate in an aquarium with no waterchanges and getting it close is just not close enough. Sooner or later any excess of nitrates, phosphates etc not being used up by the plants, will with no water changes build up until it eventually causes problems. I do weekly waterchanges of 30-50% depending on how much time I take gravel cleaning & I do daily 10% changes when raising fry.

Actually, even nature isn't balanced and every lake and stream gets it's periodic water changes, it's called rain. It's also a pretty common phenomenon for lakes to get more and more nutrient rich as you go down the watershed.

So if Mother Nature needs to do water changes, you should probably do them in you aquarium. The amount varies though, but more fish = bigger water changes.