How often can I siphon a tropical freshwater tank?

Question
I have experimented and found that you can siphon 35% of a tank at a time without fish dying.  I want to get the Maracyn II and CopperSafe out of the tank as soon as I can.  I didn't have the cartridge in the filter during treatment & still don't.

How many days later should I siphon out a tank after it is done siphoning out 35%?  If you don't know what will be safe can you give me the % that will be safe and the amount of days I should wait after siphoning to do it again and again?  Thanks.

Answer
Hi Dipan,
There really should be no problem when changing out a percentage of the water. The only things that can kill fish during water changes are drastic temperature fluctuations or drastic chemistry changes (especially with tanks that haven't been changed in a good while) and chlorine/chloramine that is present in the fresh tap water used. -Make sure you are using a water conditioner -everytime- you do a water change.
*Make sure to match the temperature of the new water as close as you can to the tank's temp.

Unless you are keeping extremely delicate species, most fish do very well when these precautions are taken.

You should be able to change up to 50% a day if you condition the new water with water conditioner and match the temp or at least get it a couple of degrees warmer.

I would also run some carbon in your filter to remove the excess medications.

Good luck I hope this helps!
Susan~