Cleaning my tank

[Lamie]

I have a 70litre fresh warm water tank with 9 tetras. I have been unable to clean my tank for about 3 weeks. I remember seeing something on here about slowly doing the water change like 10% each day for a week and 20% for next week. Is somebody able to guide me on the best thing i need to do to get my tank clean again.

 

[Boundava]

Is the water from your tap different than the water that's in your tank?
If it is then I guess you can do a water change that way, however you don't usually do a gradual water change over days but a single water change usually on a weekly basis.
When you are changing the water you remove at least 30% of it although I like to do more of a 70 to 80% water change depending on how stocked your tank is. Then you replace the water with water of similar water parameters.

For example, the majority of my tanks are just regular fresh water from the tap, I just add a water conditioner when replacing the water. I do have a few tanks that are soft water/blackwater and I use a RODI system and prefilter the water when I need to do water changes to those tanks. I also add a water conditioner to this water before replacing it.
I also have a brackish and two salt water tanks and will replace the water that I removed from the tanks with salt water.

For all of these tanks when I do a water change I will gravity siphon the water out and then replace the water with treated water of the same temperature of the tank I removed it from. A neat tip is that if you add cooler waters to tropical tanks you can usually get the fish to spawn as the cooler waters replicate rainy seasons. I have has many tetras, Cory and plecos breed after a large water change with a cool water replacement. I am not talking icy cold, but a couple degrees cooler than usual.

Hope this helps.

 

[Lamie]

Is the water from your tap different than the water that's in your tank?
If it is then I guess you can do a water change that way, however you don't usually do a gradual water change over days but a single water change usually on a weekly basis.
When you are changing the water you remove at least 30% of it although I like to do more of a 70 to 80% water change depending on how stocked your tank is. Then you replace the water with water of similar water parameters.

For example, the majority of my tanks are just regular fresh water from the tap, I just add a water conditioner when replacing the water. I do have a few tanks that are soft water/blackwater and I use a RODI system and prefilter the water when I need to do water changes to those tanks. I also add a water conditioner to this water before replacing it.
I also have a brackish and two salt water tanks and will replace the water that I removed from the tanks with salt water.

For all of these tanks when I do a water change I will gravity siphon the water out and then replace the water with treated water of the same temperature of the tank I removed it from. A neat tip is that if you add cooler waters to tropical tanks you can usually get the fish to spawn as the cooler waters replicate rainy seasons. I have has many tetras, Cory and plecos breed after a large water change with a cool water replacement. I am not talking icy cold, but a couple degrees cooler than usual.

Hope this helps.

Thank you. So it doesn't harm the fish if I haven't done a water change for 3-4 weeks. I can still do 4 buckets water change with no affect.

 

[seangee]

I do have a few tanks that are soft water/blackwater and I use a RODI system and prefilter the water when I need to do water changes to those tanks. I also add a water conditioner to this water before replacing it.

Just FWIW there is no need. I use RO water and never use a conditioner. The only purpose of the conditioner is to neutralise chlorine (and sometimes heavy metals). RO removes these anyway.

 

[Boundava]

Just FWIW there is no need. I use RO water and never use a conditioner. The only purpose of the conditioner is to neutralise chlorine (and sometimes heavy metals). RO removes these anyway.

Unfortunately the RODI does not remove chloramine unless you buy a specific addition or special membrane that will remove the chloramine. This is why I also add water conditioner to the water.

 

[Boundava]

Thank you. So it doesn't harm the fish if I haven't done a water change for 3-4 weeks. I can still do 4 buckets water change with no affect.

You should be fine, just match the current water parameters ( pH, hardness, approx temp).

 

[seangee]

Unfortunately the RODI does not remove chloramine unless you buy a specific addition or special membrane that will remove the chloramine. This is why I also add water conditioner to the water.

Technically the RO membrane should not be used to remove chloramine (or chlorine) because those substances will damage the membrane. For his reason most RO systems use one or more pre-filters to remove what can be removed before the water reaches the membrane. In my case the 2nd filter is GAC which removes both chlorine and chloramine. In reality it only removes around 98% of this but that leaves it at an undetectable level.

Please note I am not posting to disagree. If there is detectable chloramine coming out of the RO system chances are your membrane is damaged and there could be any number of things left in the water which you may have assumed would be removed by the RO process. Typically the DI filter goes in position 5 in the diag below.