How often is too frequent water changes when tank cycling?

[Love Animals]

Hi,

I am cycling a 90L AR620 tank at the moment with 5 zebra danios, they've been in there for 4 days now. The tank also has 3 aquatic plants that were in for about a week before the fish were put in. I have made the cardinal beginners mistake of overfeeding my little dudes (was a bit heavyhanded with the food) and my tank is now slightly cloudy/green. I've done my first 10% water change using a gravel cleaner to get out some impurities. How often can I do a water change so that I can keep clearing the water but without taking all my growing good bacteria with it? Thanks heaps in advance

[Ira]

Hi,

I am cycling a 90L AR620 tank at the moment with 5 zebra danios, they've been in there for 4 days now. The tank also has 3 aquatic plants that were in for about a week before the fish were put in. I have made the cardinal beginners mistake of overfeeding my little dudes (was a bit heavyhanded with the food) and my tank is now slightly cloudy/green. I've done my first 10% water change using a gravel cleaner to get out some impurities. How often can I do a water change so that I can keep clearing the water but without taking all my growing good bacteria with it? Thanks heaps in advance

If your test kit is saying there's ammonia in the water then you're not changing too much. Especially if you're doing a little change like 10%/day that's barely worth worrying about. 25-50%/day should be fine.

[Love Animals]

Thanks, actually i don't have an ammonia test kit, only a pH one at the moment which is saying 7. I will do 10% water changes every second day for a week and see what happens. My zebras and plants are doing well and are happy, so i can tolerate the slight greenish tinge for a while.

[Aquila]

Remember that the vast amount of your good bacteria is not actually suspended in the water. It grows on surfaces live your gravel, ornaments and filter...hence the importance of increasing the surface area in your filter. As Ira said 25% is good. Remember that not changing too much water is for the benefit of the fish having stable parameters (pH, temperature...etc), not for the bacteria. I would do this change about twice a week at the moment so that ammonia doesn't get a chance to build, but once your bacteria colony grows once a week (or even once every 2 weeks) will be sufficient providing there are no mistakes with over feeding. Remember to never rinse your filter media under tap water (this will kill your bacteria), instead clean it in a bucket of water fro myour tank.

[Jennifer]

The amount and frequency of water changed can vary a lot but is generally a balance between maintaining a stable environment for the fish and keeping the water in good condition. Frequent small water changes can be better for sensitive fish - this way they aren't subjected to a big change in water parameters all of a sudden. The fish you have aren't overly sensitive but like all fish they will not do well if the ammonia reaches a toxic level. During cycling you would ideally test ammonia daily to make sure it isn't too high and if it is too high you would do a 20 - 50% water change to bring the ammonia down to a safe level.

Don't be concerned about the green water right now, it won't harm your fish and will help to keep other algae at bay. If it bothers you a lot, you can turn off the lights but be sure to keep a close eye on the fish - if they are breathing hard that is a sign of ammonia toxicity.

The main thing you should be wary of is overfeeding. The more the fish eat, the more they produce ammonia and it can quickly reach toxic levels in a cycling tank. Fish can go for some time without feeding so it may be best to cut right back (or stop feeding entirely for a week or so) until the filter is cycled.

[Ira]

I'm more of the opinion that more and larger water changes keeps the water more stable and clean. Keeps it more stable with your water supply rather than whatever your tank contents and inhabitants end up turning it into with their contaminants.

[Aquila]

True...unless you are aiming to keep it at a low or high pH.

[Love Animals]

Ok thanks all. I actually did a larger water change today about 30%, so now I think I'll not feed them for a few days and let the tank get on with cycling, and watch for any signs of fish distress.