Peter, have you checked for flukes? other parasites?
Nitrites?

9 pH is not really that high as long as it's stable.
A lot of people run 9 all the time, especially in So Florida. Our water comes out of the ground at a little over 9, and most people run flow through systems.

pH can be a problem if your pH was low before, then adding new water raised the pH a lot higher, which it can do.

It can make a low ammonia level suddenly toxic.

For some reason, fish tend to get parasites after their ponds were cleaned too.

HTH

Hmmm.....you may have stirred up some nasties that irritated the fish gills or skin. Did you use dechlorinator when adding fresh water? Chlorine will also irritate gills and skin. Corrie is spot on regarding ammonia levels. The higher the PH the more toxic ammonia is. Also if your pond has alot of suspended algae then the PH will rise during the afternoon when the sun is strongest.

Another thing Peter. With the fish load you have I think it would be best to perform weekly water changes of about 10% with dechlorinator. If you are feeding heavy (which you should be doing all July and into August) then you might do 15- 20% weekly. With regard to the lilies.Two of my water lilies have yellow pads too. To some degree when new leaves are emerging, some older ones need to die. I don't fertilize mine or use soil as the primary pond focus is the fish.

Regards,
Lisa

No I have not checked for them, I was under the impression that you needed a microscope to do so? In the past i have used MelaFix, it's a Anti-Baterial rinse that goes into the pond. Would that work for parasites etc...?

I was also thinking of adding some Dechlorinator due to the town water I used?

Peter, if you did a 15% water change,then you only added 15% of whatever level your city water is for chlorine or chloramine. I don't think 15% would be high enough in an established pond to make any difference.

Read what Lisa said about green water/algae, it can really mess with your pH too.
Check your pH three different times. Real early in the morning before the sun gets on the pond, late afternoon after it's been in full sun all day, and again late at night. See if you get the same reading each time. If you don't you need to buffer your water.

Then check your source water pH.

I think you have a parasite going on. MelaFix won't work.
A lot of parasites will knock a fish down really fast and you would see fish at the surface gasping for air, laying on the bottom, or even dying off. That narrows it down to what parasite you might have.
I would guess flukes. Fish scratch, jump, and will sometimes jump out of the pond with flukes.
Pull a few out and look at them real close all over. Red dots, bacterial infections/sores, etc. Lice, anchor worms, that's things you can see.

The 4 big ones have been lying on the bottom alot or under the water falls....... But they have been eating and sometimes have bursts of energy.

Now I am really getting bummed, so what is the best method to treat them for flukes or parasites?

Peter, first eliminate everything else that could be going on.
Check you pH, different times, to be sure it's stable.
Check the pH of you source water to be sure it wasn't just a too fast pH change.
Check ammonia, nitrites, and even nitrates, to be sure they are not out of whack.

You really need to get all of that out of the way first, before you start treating for parasites, if in case you do have parasites.

While your doing that, search for info on flukes, costia, ick, etc different parasites

prima fix works for perisites and malafex for bacteria.

i use ph stabilizer and buffer in my pond this keeps my ph at a stable range of 7.0 to 7.5. since i have very soft watter this is a must for me.

i hope all goes well for you and your fish. i know how hard it is to deal with these issues.

good luck laura

Thanks everyone for the help, I am going to purchase "Prazi Pond" for the parasite issue and de-chlorinator for the Ph level.

I have one last question which I am trying to sort out, can I use them together ?

It seems I can't use anything once I use the Prazi but I guess the Ph level are the lesser of two evils.....

OK.....slow down a second. First.....dechlorinator will not do anything for pH. But if your pH is stable, you don't need to do anything for it. Check you kH. That is the level of alkalinity, which is the stabilizing factor for pH. Do not do anything to lower your pH or you may kill the fish. Fish cannot handle a rapid decrease of pH. You DO need dechlorinator though, because of your city water. Make sure your dechlorinator also handles ammonia, because your city water probably has ammonia in it. Ammonia will make fish flash and also lethargic, like you are describing.

Prazi pond is not an all-purpose parasite treatment. It only treats for flukes and multiple treatments are necessary. It can be used along with dechlorinator. But don't treat for parasites yet....your fish issues are probably due to water quality and not parasites.

So get a test kit....the kind that uses drops and not the strip kind. Check for pH, kH, ammonia and nitrite and post the results here. Also check the pond temperature.

If the larger fish are hanging out in the waterfalls, there is a very good chance your oxygen levels are too low. Low oxygen affects larger fish first. They are hanging out by the waterfalls because oxygen levels are highest there. You need to get some aeration going in that pond as soon as possible or you may lose them, especially the big ones.

ccoombs may have hit the nail on the head concerning your water temps and the low oxygen levels that warmer water has. Please add extra aeration as suggested. Another pump or air bubbler would help.

Please do not add ANY chemicals until you know what you are treating. The Golden rule of medicine that applies to ponding is "At first do no harm". Check you water, add some shade too if needed.

Good luck. Keep us posted.

Lisa

Guys maybe I'm reading this wrong, but Peter didn't say all his fish were just hanging out "in" the waterfalls.

He said the fish were flashing, jumping at the surface, and "only" the four big ones were laying on the bottom "or" under the waterfalls.

He has 25+ koi in the pond, if it was an oxygen problem they would all be at the surface.

If something has compromised their gills, this is exactly what you would see.
Flashing and jumping are not what you would see with low oxygen.

Actually, low oxygen affects the big ones first. Smaller fish can do quite well at lower oxygen levels. Since it's only the 4 big ones hanging out under the waterfalls, that suggests to me that there is an oxygen problem. And I did not suggest that low oxygen levels were the ONLY problem, there is something else going on as well. That's why I requested an ammonia reading. High ammonia levels will cause fish to lay on the bottom. Compromised gills normally causes fish to gulp air from the surface and let the bubbles come out across their gills (called "breaching").

Hi guy's,
I well I am back to normal, but not without a casualty...

I purchased a complete test kit as recommended and all was great, Ammonia, Nitrates, PH.. all perfect readings.

So then I put in Prazi Pond as directed in order to treat the gill flukes. It took approx a week to see results i.e. the bigger fish swimming around less lethargic, no flashing and most importantly not lying below the waterfalls.

But unfortunetly I wasn't fast enough on the second day after putting in the Prazi, one of my favorite 17" Koi was floating.......

I read that it is a good precaution to do a second treatment 1 week later incase of baby gill flukes so I am going to do that next.

I wanted to say thanks to you guy's for all the advice and input, other than water condition problems this was something that makes you feel like all your Koi are about to be wiped out. A little nerve racking to say the least.. and then having to wait for UPS delivery .....

Thanks again,
Peter