Water Changes.

[geordie24sas]

Just a quick question.do i need to do water changes every week still even if my levels are ok?
I cycled my tank which took 3-4 weeks,i then tested and my ammonia was 0 nitrite 0 and nitrate 40.i added 5 cherry barbs then a week later i tested the water again and got the same readings ammonia 0 nitrite 0 nitrate 40.so is it best to do weekly water changes still or water change when i get ammonia and nitrite etc showing. Its a 166L tank.

Thanks

 

[dannybgoode]

In a properly cycled, appropriately stocked established tank your ammonia and nitrite should always read 0 regardless of water changes. Your nitrates will rise over time though and ideally should be kept under 40ppm but 80ppm is acceptable.

You keep the nitrates down by water changes.

Different people do different things. I have a plec so vac my sand every couple of days which does about a 15% water change and then do a bigger 33-40% change at the weekend.

Changing the water also replenishes vital minerals etc so needs to be done regularly. How regularly depends on various factors.

Cheers

Danny B

 

[geordie24sas]

Thanks.ok so if i do water changes every wk then of say 20% that would be ok?

 

[Mikey1]

Thanks.ok so if i do water changes every wk then of say 20% that would be ok?

yes, thats fine

 

[dannybgoode]

Well possibly.

Let's say your nitrates are 80ppm and you remove 20% you're left with 64ppm.

Then, due to the stocking in your tank and the amount of nitrates in your tap water your nitrates rise 17ppm the next week youre going to be starting off at a base of 81ppm the next week and so on.

You need to measure your nitrates before doing your first water change and then again before your second water change.

If your nitrates are lower than on week one the good, if they're higher you need to do a bigger change.

Cheers

Danny B

 

[geordie24sas]

I suppose its just trial and error then really. I didnt do a water change this week end as my levels were the same as last week.as i only had 5 cherry barb in the tank.

 

[snazy]

How do you know your nitrAtes are 40ppm and not 50ppm or even 80ppm. If using the API test it's hard to tell. On my API liquid test if I see "red" colour on the tube for nitrAtes, then I am not doing enough or big enough water changes.
Generally, regardless of the readings for nitrAtes, the more often you do water changes, the better. If you want to really see how bad your water goes over time in the tank, get a TDS(total dissolved solids) meter. This would test for everything, like organics, minerals, nitrate, and many many otheres....Then you should keep it at a certain ppm level close to your tap water and anything over would require a water change. Whether this is once a week or once two weeks, 20% or 50% water change would all depend on your tank and how fast the water gets polluted with all possible things we can't even imagine.