When to change water?

[Saxsena]

I have just upgarded from 25L tank to 250L tank.Now for my 25L tank I changed about half the tank water every week. Since I have got a bigger tank can anyone tell me after how long and how much water change is needed for a 250L tank. I have about 20 neons, 2 suckers, 1 female betta, 8 other neon sized fish (dont know the names). It has Aqua One 1000 filter on it.Also do I need to run the filter 24 hours , currently I am switching it off at night, so it runs 6 hours.I alo turn the tanks lights off at night. Please guide me.

[smidey]

i have a 200L community tank. I do a 30% water change every week. I also have a CF1000 but have the hood filter running as well which is a 900L/hr pump. these run 24/7.

[Ianab]

To be sure about water changes you really need to test the water, mainly for nitrates. When they get up close to 40 on the scale it's time to change some water to keep the levels below that.

How fast it gets there depends on tank size and amount of fish / fish food that are put in there.

You can usually go by some rule of thumb like 20% per week for a normally stocked tank. More if you have max amount of fish or big messy eaters, less if the tank is lightly stocked.

You should run the filter 24 hours, but generally the lights for about 12 hours. Some fish like to sleep, and others prefer to come out in the dark.. a bit like people

Cheers

Ian

[smidey]

but generally the lights for about 12 hours. Some fish like to sleep, and others prefer to come out in the dark.. a bit like people

I look at it like we are trying to best create a naturale enviroment so i think night time is important for them. I have noticed that if i turn the lights on in the morning before dawn & throw some food in the fish stumble round like they are waking up when they try to eat.

[SpidersWeb]

Filter must be run 24 hours to keep the beneficial bacteria that build up in the filter over time alive. These bacteria are responsibile for converting fish waste (ammonia) in to nitrite and then finally nitrate.

[Saxsena]

Thank you, this was so helpful.

[Saxsena]

Just another question. I have started planting some live plants in the Tank. I bought a air pump yesterday. Someone told me that I have to have the pump running very slowly at night for the plants. First do I have to do that or just shut it off or if Yes, than air pump has only two speed setting, which does not make much difference. Is there any DIY methods to make it slow. Thank you for all you help.

[Caryl]

You do not need an air pump at all. What sort of filter do you have? If you want to run it and can't slow the bubbles down enough you can buy clamps to put on the air hose, or use a peg.

[Saxsena]

Its Aqua One 1000

[Caryl]

Then you certainly don't need an air pump as well.

As for water changes, I rarely do them but my tank (a similar size to yours) is very heavily planted and lightly stocked. The last water change I did was mid Feb and I am about to do another one this week. When I do water changes I replace about 60L which is 6 buckets.

As an aside, I will be doing a pictorial guide to doing water changes in the next Aquarium World magazine so you will all see my before and after tank pics as I clean it out

[Saxsena]

Thank you for the information

[Ianab]

I have internal filters and airstones / curtains in 2 of my tanks. It's not necessary if you have a good filter, but it looks good, cant harm anything and gives you a backup in case your filter gets blocked up and you aren't there to notice.

If you have a filter you can probably just run the airstones when you feel like it.

Your fish shop should have a little set of valves that you can use to adjust air flow from one pump to different tanks or airstones too Doesn't cost much and makes it easy to get the airflow you want.

Cheers

Ian