PS3 said:
so how many gallons is 15 percent?? . i just got a 525 gph pump for water changesand other things if i need the extrea pump. so i figued out if its 525 an hourthen a half hour should be around 250 gph and about 20 mins thats over 100 gallons.i ran this pump last week for my water change and i timed 15 mins and it took
out about a foot or more of water.so i went to the pond calculator and i did my pond 8 x 8 oval at 1 foot of water and it said i took out 375 gallons can this be right ??
Just my opinion, but it isn't worth it to do smaller water changes to avoid using dechlorinators.
My opinion are based on these facts-
Even when using a dechlorinator your fish and biofilter will have short term exposure to chlorine. I guess after a while of 15% water changes weekly without a dechlorinator the fish will have slightly less exposure because of all the built up dissolved organics and other crud. The chlorine will busy attacking that.
There are many factors that determine what % water should be changed weekly. The easiest and most common way is by a nitrate test. To help control toxic conditions and green water algae, keep your nitrates below 50ppm. Really it should be well below 25ppm for optimum and healthy conditions.
Pond dechlorinator is such a small investment for a pond in comparison to the other things. Based on just the "rule of thumb" in your pond a 25% water change would be 250 gallons weekly. You can get a declorinator for about $40 that treats 40,000 gallons of water. That should last you over 3 years. You will have less chance of poisoning your fish and green water algae. Your pond's water will be clearer and the white on the Koi will look white, not "mother of pearl".
Water treatment facilities use different amounts of Chlorine disinfectants deppending on what contaminates they are fighting it also varries by time of year, weather and other factors. Do you know how many ppm of chlorine your water contains? Most water companies are using chlorimines or ammonia and chlorine combination. This allows for the chlorine to last longer then normal. Disapation of chlorine varies per condition. If the water is warm and is agitated by a fountain or waterfall it will disapate faster then cool still water. There are so many variables it could take a few hours, a day or a few days for chlorine to disapate. Meanwhile your fish are being exposed to this, as well as your bio-filter.