Charles, San Jose


We finally got the pond running late yesterday.  I got a new slideshow up.
The fish look happy.  Hope you like it, and…
Happy Koi Keeping,


Hi Don,

Thank you for your help with the filter installation. The slide show looks good.   I appreciate your help very much.



My reply to Vinh:

Thanks Vinh,

Install looks pretty good I think.  I think Mel is going back tomorrow to finish up a couple of details.  There’s a couple of things you might be able to help with.

For some reason your Father likes to run the water level low.  I’m not sure if he’s worried about the koi jumping out or predators, but the water level is always very low whenever I’ve seen it.

Last Wednesday we discussed this and I hope he understands.  I explained the trickle feed and told him he should be running the pond about 5″ below the top at the waterfall end.  It will be closer to the top at the other end since the edge of the pond is not level.

He’s planning on flushing the filter ever third day.  I think that will be about right since the filter is so large compared to the pond.  Flushing every day would use too much water.  I explained that he should adjust the trickle until it just fills up by the third day.  The flush will take it down about an inch or so, and the process starts all over.

This provides the best possible water change and should keep his water in good shape.  I expect ammonia and nitrite to be up for a few weeks.  It takes about 4-6 weeks to mature.  I asked that he not add any additives as they will just prolong this process.  As long as the koi look good there should be no problem.

They looked great on Wednesday.  Very friendly and active and were eating well.  That’s the best sign that the filter is working properly.

I tested the flow on Wednesday.  It was about 1,575 gph.  That’s right where I wanted to see it.  That turns over the pond often enough and is slow enough to allow the filter to process the water properly.

I hope you’ll encourage your Father to keep it at that level.  If he turns it up too high, the filter will not have enough dwell time to convert the ammonia and nitrite.

You can easily check the flow level with a yard stick, a digital watch and a plumbers helper.  You stop in the inlet with the plumbers helper and time the period it takes the water to drop two inches.  This formula gives you the flow rate: F= 10.5/time x 3600.

I was finally able to see the white marks clearly.  It looks like koi pox to me.  I had one of my koi with this in the Spring.

Unfortunately, there is no cure.  It is caused by a herpes virus, not THE herpes virus, but another one and is incurable.  Fortunately, it does not usually cause much of a problem, but it doesn’t look very good.  I suggested he get the vet to take a look to make sure.  I gave him her number.

If it is koi pox, the only solution is to increase the temperature.  He might want to get a small quarantine system.  Since he plans to get more fish, this would be a good idea, and it’s always good to have someplace to treat a fish that gets sick.  If it is koi pox a few days in warmer water should make it go away.

I hope he enjoys the new filter.  Thanks for the purchase, and …

Happy Koi Keeping,



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