Jump to content
Danae

Question about filtration

5 posts in this topic

I have 2 fantail goldfish in a 65 lt tank. The filter is a hang on back filter but back because i keep it in my room i turn the filter off at night. Does it affect the cycle of the tank or is it ok? 

Share this post


Link to post
Share on other sites

Please read our guidelines for healthy goldfish.  You will see that your fish need a much larger tank -- 40 gallons ~= 150 liters.  You can compensate for a too small  tank by larger and more frequent water changes.  We recommend 50% changes weekly if you have 75 Liters per fish.  With only 30+ liters you should do at least two 75% water changes each week.

When you have a filter in the tank virtually all of the cycle microbes live in the filter.  They live there because they require a steady supply of oxygenated water, ammonia, and plenty of surface area to live on, and they get these in a running filter.  A filter quickly becomes the site of the dirtiest water in your system since it continuously collects debris.  The bacteria that decompose this crud grow in this environment, and, like the cycle bacteria, they need oxygen to do their job.

When you turn off your filter, no more oxygenated water enters the filter.  The decomposing bacteria use up all the oxygen, so the cycle bacteria get none and cannot oxidize ammonia and nitrite so these build up. when you turn on the filter in the morning, lots of ammonia, nitrite, and various organic compounds pour out of your tank. You can expect your fish to gradually weaken, become susceptible to illness, and eventually die.

If the filter sound bothers you, you can move the tank or use earplugs.  Alternatively, you could do 50% daily water changes which can replace filtration.

 

Edited by shakaho

Share this post


Link to post
Share on other sites

Hello, thank you for your reply i will study the link. Really 150lt?? When i did research for goldfish tank requirements most sites would recommend 20 gallons for two fish and i thought they where fine in this tank. Right now i don't have enough space for a bigger tank but a better filter would do anything? I was thinking about a canister filter that could stay on all the time because they are silent. 

Share this post


Link to post
Share on other sites
1 hour ago, Danae said:

Hello, thank you for your reply i will study the link. Really 150lt?? When i did research for goldfish tank requirements most sites would recommend 20 gallons for two fish and i thought they where fine in this tank. Right now i don't have enough space for a bigger tank but a better filter would do anything? I was thinking about a canister filter that could stay on all the time because they are silent. 

You could put on another filter, you could do more water changes. Then you also could get a plastic tub to the one in. Just another idea :) 

Share this post


Link to post
Share on other sites

You cannot compensate for inadequate volume by adding more filtration than we recommend. Filtration serves to mechanically remove solid waste and to convert  ammonia to nitrate.

Larger water volume keeps dissolved nitrate, and dissolved organic and inorganic substances under control.  You can also dilute these potentially harmful chemicals in a smaller tank  by changing more water.  

If you have a tank half as large as you should have for your fish load you can maintain water quality by doubling the water changes recommended for the larger tank.  You do lose the larger horizontal swimming area, which keeps fish active.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now