I have an established 10 gallon tank. Started it December almost 2 years ago. How often should I do a water change?
How often to water change?
- Thread starter xboxlive2020
- Start date
I do 50% weekly on all 3 of my tanks....
I figure, if you're going to do it only once a week, why not make it worth while? Now, you should be cautious about temp chngs though.....not such a big deal on the 180g, but the 29g I gotta be careful with...
I figure, if you're going to do it only once a week, why not make it worth while? Now, you should be cautious about temp chngs though.....not such a big deal on the 180g, but the 29g I gotta be careful with...
do the math
If you set up a spreadsheet, or can do the math yourself, you will see that doing a 20% water change once a week leaves you with 5 weeks worth of waste in the tank as a stable level.
My guess is that not only is 20% a week no sufficient, but that your tank may be way overdue for a cleaning which means that you need to be careful about too large a water change at the start.
What happens is that the water in the tank begins to be very different from the tap water. Evaporation concentrates the minerals in the water as you top off the tank. End products of biofiltration like nitrates build up to very high levels.
I suggest that you need to test the tank water first and then you will know what to do. If you do not have an Aquairum Pharmacuticals test kit, perhaps you can take a sample to the pet store to get ammonia, nitrite, nitrate, pH, KH, and GH tested. Also test the nitrate, pH, KH and GH of your tap water after it has sat overnight.
If there is much difference in the KH, GH and pH, or high nitrates (over 40ppm) then you need to do small (10-20%), frequent (every few days)water changes to get the fish used to tap water again.
Then, buy a nitrate test kit and a pH test kit. Change water when the nitrates reach 40 ppm to reduce to 10 or 20 ppm. Check pH from time to time, especially if it tends to drop. If the KH is low and declines, then pH may decline over time and a sudden pH crash is not good for fish, generally a water change will help maintain the KH.
If you set up a spreadsheet, or can do the math yourself, you will see that doing a 20% water change once a week leaves you with 5 weeks worth of waste in the tank as a stable level.
My guess is that not only is 20% a week no sufficient, but that your tank may be way overdue for a cleaning which means that you need to be careful about too large a water change at the start.
What happens is that the water in the tank begins to be very different from the tap water. Evaporation concentrates the minerals in the water as you top off the tank. End products of biofiltration like nitrates build up to very high levels.
I suggest that you need to test the tank water first and then you will know what to do. If you do not have an Aquairum Pharmacuticals test kit, perhaps you can take a sample to the pet store to get ammonia, nitrite, nitrate, pH, KH, and GH tested. Also test the nitrate, pH, KH and GH of your tap water after it has sat overnight.
If there is much difference in the KH, GH and pH, or high nitrates (over 40ppm) then you need to do small (10-20%), frequent (every few days)water changes to get the fish used to tap water again.
Then, buy a nitrate test kit and a pH test kit. Change water when the nitrates reach 40 ppm to reduce to 10 or 20 ppm. Check pH from time to time, especially if it tends to drop. If the KH is low and declines, then pH may decline over time and a sudden pH crash is not good for fish, generally a water change will help maintain the KH.
I have to question the math a bit (but NOT the advice). I would agree that 20%/week would leave you with roughly 5 weeks of waste if the following cases were true:
1) ALL of the waste was contained in the water column and not the filter and gravel. If, when you water change, you vaccuum the solid waste from the substrate, and shake off the excess solid waste from your filter media, I would think you would be removing more than 20% of the waste in the tank.
2) Water didn't mix and you can change 20% this week, 20% of the water the next week, but only water that was there the first week, etc. This one is a bit of a nitpick, but still true.
I think you have a good rule of thumb, but unfortunately, just saying "do the math" isn't exactly true, imho. Again though, I would still follow your advice, especially if the tank parameters are very different from the tap's parameters.
1) ALL of the waste was contained in the water column and not the filter and gravel. If, when you water change, you vaccuum the solid waste from the substrate, and shake off the excess solid waste from your filter media, I would think you would be removing more than 20% of the waste in the tank.
2) Water didn't mix and you can change 20% this week, 20% of the water the next week, but only water that was there the first week, etc. This one is a bit of a nitpick, but still true.
I think you have a good rule of thumb, but unfortunately, just saying "do the math" isn't exactly true, imho. Again though, I would still follow your advice, especially if the tank parameters are very different from the tap's parameters.