Help! Koi dying during water change!

[bandita]

Since the last time I posted, I've upgraded to a 450 gal pond for my 2 kois, algae eater, and corey catfish. Kois are about 10". They moved to their pond several months ago, and have been doing great. I use a water conditioner.

I came home from vacation, and water was really dirty. Yesterday, I decided to completely clean it. Sides and bottom were caked in algae, and I scrubbed it all off. By the time the water got low enough where I could catch the fish, water was VERY dirty. I put clean water in a storage tub and put the fish there. By the time I finished cleaning the pond and filling it with water, it was already about 2am. All the fish still seemed to do fine in the tub, so I decided to wait in the morning to transfer them back to the pond (so that I can view/monitor them clearly). Next morning, about 7:30am, I find my fancytail koi dying at the bottom of the tub! Looks like he's gasping for air. I immediately put all the fish back in the pond, since I have the waterfall on and water conditioner. The only thing I can think of is that I had no aerator on in the tub. I didn't think that would be an issue, since it's outside, and I figured that if they get low on air, they'd gulp from the surface, and this was just temporary.

The other fish seem fine, but the dying one laid at the bottom of the pond, which is about 2 feet deep. I wen to check the height of the pond at about 8:10am, and found him at the top (mouth just below the surface of the water). At least he's right-side up, instead of lying on his side at the bottom. Does this mean he's getting better, or is he getting closer to dying?

I also found that the water temp of the tub was 74 degrees, and the pond is 78. Is this considered to be a drastic change? When I do these water changes, I normally sit them in a little pail of water in the pond, so that the change will be gradual, but I acted in panic this morning. I wanted to get the fish back to their normal water condition (but much cleaner) asap. What's my best course of action to try to save my fish? The others still seem good.

 

[bandita]

I'm not sure if I used the right terminology when I said that I use "conditioner" in my pond. It removes chlorine and chloromine (not sure if that's the same thing as a conditioner. The PH level for our local water is about 7-8 (neutral or slightly alkaline).

 

[FWFishTanks]

I'm not sure if I used the right terminology when I said that I use "conditioner" in my pond. It removes chlorine and chloromine (not sure if that's the same thing as a conditioner. The PH level for our local water is about 7-8 (neutral or slightly alkaline).

That's water conditioner, so it's not chloromine or chlorine. Does the pond have any surface agitation to give the fish access to dissolved oxygen in the water?

 

[bandita]

Yes, my pond has a fountain (even though I accidentally called it a waterfall in my posting). Anyway, my fish sprung back to life several hours later, as if nothing happened! Now I just want to prevent my pond from ever getting that dirty again to the point that I need to do a complete cleaning, 100% water change. I bought a new solution called Clear-Zyme that's supposed to dissolve ammonia and sludge. I followed the instructions in adding the proper amount. When I do the 20% bi-weekly water change, am I supposed to also add a little more of the Clear-Zyme and the other solution that removes chlorine/chloromine?

 

[jlk]

Does your pond have an appropriate capacity filtration system?




Sent from my iPhone using Aquarium Advice

 

[bandita]

Yes. Filter system came with my pond kit.

 

[jlk]

Much like aquarium package deals, pond packages are often quite insufficiently filtered. With two very large koi and issues keeping your pond clean, it honestly sounds like you need to upgrade or supplement your filtration system with additional means of filtration. Fountains are not filtration but simply provide a means for aeration.

Unless your algae problem is very severe (as in your fish can no longer swim freely), I would suggest not scrubbing out the pond on a regular basis (or at all). Just remove plant and leaf debris as needed. Algal growth is part of the natural ecosystem of a pond and provides food for your fish as well as a home for your good bacteria and a variety of micro organisms. An excess of pond algae should be dealt with by eliminating the cause (such as high nitrates, too much light, etc) or it will simply continue to be an issue. Adding plants (particularly those that provide pond cover to lessen light exposure and remove excess nitrate) is one of the best means for maintaining a healthy pond environment along with a regular water change schedule due to the limited size. Hope this helps a bit! Please ask any questions!

 

[bandita]

Thanks. The fountain I have actually does have a filter attached to it. I think it does a pretty good job in picking up a lot because everytime I rinse it, there's a lot of debris. I think that the pond problem happened while I was on vacation because I had asked my neighbor to feed them since the hurricane we had damaged the food I had in the automatic feeder, and I didn't want to take the chance of that happening while I was gone. I found out when I came back that my kois don't like being hand-fed, which is a new problem I'm having now. I've been trying to ween them off the auto-feeder, now that my workhours are back to normal (I use to leave early in the morning in the dark, and return at night, so they wouldn't be able to see the food). But now, they won't even eat from me. I've been scooping up all the leftover food after about 10 min, since they won't touch it, even when I walk away for a while. Going back to the automatic feeder tomorrow, since it's been a while since they've eaten. I got some guppies yesterday, since I read that they can train kois. I also got some water lettuce and hyacinth today, with the same idea that they'll provide more oxygen (in case the power goes out someday) and help keep the water clear. Before, I only had a taro plant, which does well with my kois since they don't destroy it. I devised a pot for the water lettuce and hyacinth in a way so that the kois won't be able to access and destroy it (which they will, as they did with the water lillies and anacharis I tried before. Eating the plants would be one thing, but it's like they chew on it, and spit it out, causing a mess.) I just hope my new plants do okay because my pond is in a covered patio, and only gets a couple of hours of direct sunlight per day. The guy I bought the plants from has a goldfish/guppy/crayfish pond as part of his aquaponics system, which I was really impressed with. He's had it for almost 3 months, and water is clear, without a traditional filter and without him ever cleaning it. I might consider this.

 

[bandita]

A couple of weeks ago, I received a message in my email inbox (can't remember whether it was from this forum or somewhere else), from an individual who commented that they had a pond for several years and learned a lot in keeping it clean, and they shared their personal email address with me for if I wanted some tips. I wanted to reply, but was at an inconvenient location at the time, and now I can't find that email for the life of me! If you're that person, can you send me another pm? I would love to hear from you. Thanks.