Now, Why Can'T I Top Off A Tank?

[Miss Dib Dabs]

*Tries to imagine doing a 50% w/c every week on her tanks* Nope, it wouldn't happen. It did when I was breeding and when I kept unfiltered tanks for the betta's. More often probably. I only do them now to remove the poo which some of my more messy fish leave on the substrate. Never comes close to 50%.
Bygones, anyway, yes do top off the water if it needs it. I do regularly, especially in summer. The peeps are right, it isn't the same as a w/c, obviously but sometimes necessary if water evaporation is a problem.
P.

 

[Mr Spoon]

you should be doing weekly changes on every tank of about 50% unless the stocking is so low, you can probably get away with 30%.

i know some people do W/C's every 6 months or more, as they have special tanks that are low tech and low stocking. but they are exceptions and these people know what they are doing. i woulodnt really recommend it.

Sorry but I don't agree. 50% water change every 2 - 3 weeks is plenty. My water stats are allways perfect. I can understand if your keeping discus or are over stocked.

 

[mini_matt]

i would just change your 50% every2weeks to 25% every week,helps to keep nitrate down and keep ur water nice and aired ammonia and nitrite should stay at 0 even if you left it longer but nitrate level would rise unless the tank is high planted

 

[Nick16]

you should be doing weekly changes on every tank of about 50% unless the stocking is so low, you can probably get away with 30%.

i know some people do W/C's every 6 months or more, as they have special tanks that are low tech and low stocking. but they are exceptions and these people know what they are doing. i woulodnt really recommend it.

Sorry but I don't agree. 50% water change every 2 - 3 weeks is plenty. My water stats are allways perfect. I can understand if your keeping discus or are over stocked.

what about undeteced spikes? if you suddenly get a spike that can go unnoticed unless you are testing you water every 6-12 hours, it would be another 2 weeks until you changed the water.
your playing russian roulette there mate, one day the chamber wont be empty so to speak.

 

[OldMan47]

Mature tanks, when you are not adding fish, do not get spikes Nick. I do water changes based on stocking levels and the type of set up I am working on. The heavier stocked tanks get more water changed than the lightly stocked ones, and the NPTs get very few water changes. I test water whenever I set up new tanks to make sure things are ready to use and if I suspect there might be something wrong with a tank. Most of the time I am aware whether a particular tank is well enough established to not need any testing. If it needs it I do it. The only time I stress over testing is if I get a new tank, new fish and have done a crisis filter clone. In a situation like that I often monitor the water closely for a week or more to make sure the clone has taken. If it has not, I do 90% or larger water changes while my filter finishes cycling. Even a poor clone will usually finish in a week or less. An immature tank like that can indeed have a spike or two and it gets daily testing until things settle in properly. Another time that I find testing useful is if I have added a lot of fish to a tank. In that case I test long enough and often enough to determine my water change schedule for that tank.

 

[Mr Spoon]

Mature tanks, when you are not adding fish, do not get spikes Nick. I do water changes based on stocking levels and the type of set up I am working on. The heavier stocked tanks get more water changed than the lightly stocked ones, and the NPTs get very few water changes. I test water whenever I set up new tanks to make sure things are ready to use and if I suspect there might be something wrong with a tank. Most of the time I am aware whether a particular tank is well enough established to not need any testing. If it needs it I do it. The only time I stress over testing is if I get a new tank, new fish and have done a crisis filter clone. In a situation like that I often monitor the water closely for a week or more to make sure the clone has taken. If it has not, I do 90% or larger water changes while my filter finishes cycling. Even a poor clone will usually finish in a week or less. An immature tank like that can indeed have a spike or two and it gets daily testing until things settle in properly. Another time that I find testing useful is if I have added a lot of fish to a tank. In that case I test long enough and often enough to determine my water change schedule for that tank.

Oldman47 knows what he's talking about. The only time you get spikes in a mature tank is if you do something silly like add loads of new fish at once, or replace alot of filter media, or start over feeding.