After testing pH, ammonia, nitrates, etc and doing some parasite scrapings; I’m wondering if my koi pond is lacking oxygen. There are test kits and devices (expensive) available but would take some time to ship. My question is, would raising the aerator stones be beneficial? I’ve always had them sunk to the bottom. This spring has been especially hard on my fish and it looks like I have another two comets who aren’t doing well and exhibiting the same behaviors as the last two fish I lost (including one koi).
Everything I am reading says that larger fish are affected first because of lack of oxygen but I’m not sure if that is always the case. My bigger koi are seemingly okay at the moment .
Edit: I do have a small waterfall and this is my sixth year with the pond. No new fish added. All original

Ashley, what is the depth of your pond, the surface area, the total gallon capacity and the total number and size of the goldfish and koi?

Is there any muck on the bottom that could be off gassing?

Keith

Oh gosh measuring…ughh
It’s about 700 gallons. I have two koi who are 12-16 inches. A dozen or so comets that could fit in the palm of your hand. We do a partial water change sometimes in spring and summer. Maybe about twenty percent. and we have a vacuum that helps clean off any waste/ muck on the bottom. It is honestly minimal and the water is clear to view.

Keith it is 6X9 rectangle about two feet deep

I’ll look into that!

The more surface area a body of water has, the better it exchanges gasses with the atmosphere. 700 gallons should be plenty for roughly 116" of fish, unless the pond is very deep, with little surface area for gas exchange. The more the water surface is disturbed, the faster it exchanges gasses.

After 6 six years of growth, the koi and goldfish should both be considerably larger than they currently are. Both koi and goldfish usually reach the current size of your fish at 1 year from spawn. There must be some sort of stressor on the fish, probably water quality.

Is your pond in full sunlight? How hot does the water get at it's peak during the day. Colder water holds more oxygen than warm water.

Keith

Soil in your area is naturally acidic.
Roof gutter sludge is highly acidic.

If tree canopies are present and
grew in 6 years, that is a change.
Many trees have tannin etc.

Have you salt or sodium treated?
This helps shiners big time.

We do get full sun in the day. But this is an extremely overcast part of the state. We don’t have floating pond plants yet because it is too early…last year our pond plants did not do well at all.
I feel a partial water change is crucial but Chuckie doesn’t want me digging out the pond vacuum with my back so I’ll have to wait for him. I feel helpless and stupid right now and I want to figure this out and get something done

Wright Bros, I added salinity in the fall when one of my koi had Dropsy. I would imagine it is all out by now.

When you add water is it chlorinated? Yikes.
Let it stand in the open helps this.


I should lime my pond again.
Lookin like Good year for water snakes.

We add dechlorinator but I have also filled a big garbage can with hose water and let it sit and then pumped it into the pond.

What did PH test? I use litmus lol.
What is target PH?

I test a pool, not a pond but test strips are kind of a joke. Easy, quick, but just a rough idea and not an accurate measurement. Lots of room for error. I use a 6 in 1 tester for Chlorine, PH, and Alkalinity. Way more accurate.

Anyway I came here to say that the more aeriation you have (water fall you mentioned) ((any splashing)) increases PH. So those two variables play off eachother.

With a pool you don't turn the jets to ripple the water to keep PH low, to increase PH I turn the jets up so they boil the water.

Anyway I've talked to a lot of people that don't realize that. Hopefully it helps.

Yesterday it was 8.
My pond plants last year were crappy. I kinda wondered about water quality then.

OhioBoy I have the test tubes and drops for the pond. I use the ph strips for tanning lol

So What is the target PH?

Google said: Ideal pond water parameters include a pH range of 6.5 to 8.5, a total alkalinity between 75 and 200 mg/l (or 50 to 200 ppm), and a dissolved oxygen level of at least 6.0 mg/l. Ammonia and nitrite levels should be zero, and nitrate levels should be below 30 mg/l.

Garbage bags, especially if scented, contain chemicals that can harm your fish.

Keith

I still lose fish with bubble aerators on the bottom. Pump the water and create lots of splashing when the water falls back into the pond. Works well for me.

Fisher Scientific litmus paper a joke
but you need google to guess the target PH?
Okee Dokee.
Maybe try google pond stars or some
such google expert. Good luck.