No need water change??

[aquitori]

Here in NorCal they have measured the snow pack for the year and it seems we are not in a drought situation...anyways, everyone seems to be on the same page on agreeing with it and I would too. Just to remember to declor or run a active carbon filter system..

[Roddy Conrad]

When small quantities of chlorinated tap water are added to fish ponds, the chlorine is immediately consumed and reduces the dissolved organic carbon load by converting it to chloroform which almost immmediately goes off into the air from the waterfall or aeration. I have measured this technology carefully for many years now, and it works really swell in very careful use.

The problem of course is overdoing it by adding too much chlorinated water too rapidly and killing the fish, which can and does definitely occur.

So everyone is right depending on the circumstances and limits and measurements taken during the practice.

[Lam Nguyen]

Great responses so far. I definitely agree that small continuous water changes via a water trickle is much better for the koi than large weekly or biweekly water changes. Also, lots of people think that a continuous water trickle would run up their water bill. My response is that they should have the water trickle at a rate equal to what they would change once or twice weekly.

As far as whether the trickling water should be dechlorinated first or not, I have heard both answers to this question. Some say that the chlorine from the trickling water would not build up enough to harm the koi whereas others say that it may have an effect. My answer is that if you are going to spend at least $1,000 on a koi then I would not take any chances in harming them or affecting their development.

[PapaBear]

My aren't we an agreeable bunch...
I think all the points have been well addressed. I've always been a fan of fresh water coming in either in a surface mist or some other form of well aerated/atomized method. Degassing the CO2 and most of the Chlorine before it even comes in contact with the water with the added benefit of extra aeration for the new water.

[Roddy Conrad]

In my experiments, I also carefully tested adding the water change in a spray versus underwater with no air contact. When using OUR tap water, aerating the water does NOT reduce the chlorine content. When I use the chlorine in city water to remove dissolved organic carbon content, I limit the chlorine entering the pond to a measured chlorine content of 0.15 ppm by a accurate coloimeter measurement of chlorine content. The 0.15 ppm chlorine is used up by the dissolved organic carbon content in about 1.5 to 2 hours to levels below 0.02 ppm (the limit of the colorimeter test in measuring active chlorine content). I find no damage to koi when limiting the chlorine content to these levels in relatively small water changes.

[JasPR]

Roddy! Where have you been?? JR

[Auntiesue]

I drove myself nuts one summer looking for a decent sized leak in my big pond. Finally gave up and installed an "auto fill" system with one of those house carbon filters inline. That was last spring and the summer my water was absolutely wonderful. Had that "look" to it. I now have and appreciate that leak and now hope it remains forever. I still dump my sump 2xs a week which adds about 500 gallons to the 12,000 system each time.

Here is my only concern about doing this. You just never know when the city is going to throw you a surprise like dramatically increasing the chlorine levels without warning. Locally this happens in the heat of the summer, when the flush the fire hydrants and after heavy rains. So you have to have a good idea of when you might expect your city to make such decisions. I simply called my water treatment folks and asked when they might typically increase the levels of chlorine. If in doubt, I call them at any time during the season. Sometimes the chlorine is so bad I can smell it out of the tap.

[moikoi]

the Hudson autofill comes on every 1.5-2.5 hrs for about 5-7 mins. never had any chlorine problem with our city tap water. i still do a 10% weekly W/C during feeding season from Mar-Nov. sometime i get lazy and only do bi-weekly W/C from Dec-Feb the fasting months.

[Roddy Conrad]

Quote: Originally Posted by JasPR Roddy! Where have you been?? JR

Recently, you mean? Actually at my Mother's funeral giving the Eulogy (NOT a joke!). It took me a few weeks to get myself together again after spending a few days with my very insane family of origin. All completely nuts like me......

Good to see you, JR.

About the spraying test. Our main outdoor koi pond developed a significant leak in the concrete, and it was not convenient in the middle of the summer ponding season to move all the fish, empty the pond, fix the leak. So the level dropped several inches every day, and daily I refilled the missing water with chlorinated tap water. On at least 14 days, the water was added through spraying it from the hose up into the air and letting the spray drop into the pond. On those days, the chlorine right after the water addition was 0.15 ppm, and on the other 120 days of the same water addition amount from a hose underneath the surface, the chlorine reading on the colorimeter was exactly the same 0.15 ppm. So if spraying the water into the pond gives you no detectable chlorine content, one of several things must be happening:

1. You don't have a test procedure that measures low chlorine content.
2. Your pond has such high DOC (Dissolved Organic Carbon) content it immediately consumes the chlorine.
3. Somehow your chlorinated tap water has a different active chlorine compound that actually does vaporize in a spray (most unusual, but possible I suppose.)

[MikeM]

Yep. HenryC did a test by spraying water in a bucket. No reduction in chlorine content.