Water and filter questions

[bkrengel]

Hello, I’m wondering if anyone might be able to give me suggestions on my tanks water. I started the tank in February and made the novice mistake of having to cycle it with fish in it. 1 of the 3 made it. Ammonia, nitrite and nitrate all stabilized at 0 and I made the decision to add two more fish 5 days ago. Now for the past 5 days Ammonia is .25, Nitrite is 0 and Nitrate is 5. I’m wondering what to do to get the levels back to 0 or are they safe if they don’t increase anymore? Fish are happily swimming through all levels of the tank. I also have yet to change the filter for fear of losing beneficial bacteria so I’m wondering when and how to do that? Or should I clean it in some of the water from the tank? I typically gravel clean once a week. It’s a 10 gallon tank with 3 male Molly fish.

 

[PorshaF]

Continue gravel cleaning, doing a water change once a week will drop any harmful amount of ammonia. Just check below hardscaping for poop or rotted food that they may have pushed under once In a while. When you do your water change just take your cartridge out of your filter box, swish it around in the tank water you just put into a bucket (used only for fish water) set it back in the filter box. I only do this once a month if it looks like its funky, otherwise once every two months in my filters. Carbon cartridges will last longer than the boxes say, use it until you think it's dead of carbon, then an easy switch would be media bags if your filter box has the space! Commercial chain stores have an easy selection, prices vary on locations. It is normal for fluctuations in parameters when adding multiple fish into a tank at once, just be sure to test and change water accordingly and they should be fine. Post pictures when you can! Best of luck!

 

[Byron]

You likely have a colony of nitrifying bacteria in the filter now, so keep an eye on ammonia and nitrite, and do water changes if nitrite appears to keep it at zero.

Looking ahead, a 10g is not sufficient space for three mollies. This fish will grow to 4-5 inches (males tend to be 3-4, females 4-5). They also must have moderately hard or harder water; do you know the GH (general hardness) of your tap water? The pH must b above 7, but the GH is the critical parameter here.