Water Changes And Algal Bloomage

[Herpetology!]

Since I'm sort of new to the maintenance of closed system non-petstore tanks, I would like some guidance on warning signs.

When do I know that it's time for a 20% water change? When do I know it's time for something more drastic than a 20% water change?

In the last 24 hours we FINALLY have some algae for our fishes to graze on. It's arriving fairly fast; what started as a small spot is now 5 or more spots. We're thinking maybe a snail of some kind could help control it until we get some more live plants to help choke it out. Do snails such as mystery, zebra or apple cause negative effects such as more waste product harmful to the fish? Would it even count as adding another fish?

Thanks.

 

[dwarfgourami]

I think most of us find it easiest to do a 20-25% water change once a week as a matter of routine, rather than running a closed system. It's really quick and easy once you get the hang of it, and for the fish I imagine it's like opening the window of your bedroom- that little bit of freshness that makes all the difference.

If your fish look in any way under the weather, your first action should be to test the water for ammonia, nitrites and nitrates- if there are any readings of ammonia or nitrites, and if your nitrates go higher than 10 ppm or so over the tap water, then it might be time for something a bit more drastic.

Snails do add to the bioload, but it's hard to tell exactly how much. Depends on size of snail for one thing.

 

[andywg]

The time to change water is generally given as when the nitrates go too high.

The lowest figure I have seen in scientific studies for long term damage to fish is 100ppm, though a number of people get upset at the thought of anything more than 40ppm.

It is easiest just to stick to 10-20% water changes per week