My husband and our regular non-Koi worker built our pond themselves. I figured that they knew about maintenance procedures, frequency of maintenance, risks of lack of maintenance, etc.
A few months ago I made a post regarding an algae problem. https://www.koiphen.com/forums/showth...t-Big-vs-Small I received a number of replies, but I was a bit stressed and turned off by the technical nature of some of the responses. Other than fixing our UV and becoming more vigilant on cleaning the filter baskets, netting the leaves out of the pond and nagging my husband to quit feeding the fish so much (he didn’t change), there weren’t any significant changes. The algae persisted, but the fish seemed to be (to me at the time) in good health. Then the weather cooled and the algae wasn’t much of a problem. Water was more clear than cloudy……but never really great.
So spring/summer came and the water heated up. The algae came back with a vengeance. It seemed to me that the fish were lethargic, and one fish was spending all its time on the bottom, rarely moving, with its fins clamped, not even surfacing to eat. Obviously it was having a serious health problem, but I didn’t know what it was. I was tempted to just cull the fish, but instead decided to try to nurse it back to health.
Still not really knowing what I was doing but having read up on the symptoms, I purchased some Nox-Ich, even though I could not see any spots. As soon as I dumped the Nox-Ich in the pond, the sick fish started vigorously moving. Obviously it had some sort of parasite, and the parasites were not happy about the Nox-Ich, making the sick fish uncomfortable. I treated over three days, and the fish was better, not great, but at least was surfacing and trying to eat. I also noticed that it was blind, so I had to do some careful hand feeding.
Shortly thereafter, the problems seemed to return to that fish. I purchased more Nox-Ich, and this time did a series of three three-night treatments, skipping a day between each series. The fish was significantly better, but still not great.
During this time I also did a lot of reading on pond maintenance and water quality. I realized that we were doing A LOT wrong, and it was only by sheer luck that we didn’t have a complete fish die off during our 8 or so years of doing not much more than netting the waste and adding more fish.
So…..in an effort to help newbies avoid similar problems…..I am going to outline everything I did to nurse the pond back to health.
1. I discovered that our timer on our aerator was broken……so other than our meager waterfall, there was no oxygen being infused into the pond. Not only that, my husband had only set the aerator to run for about two hours per night…..in the middle of the night while we were sleeping….when there was nobody up to notice whether the aerator was actually coming on. We now have a new timer, which runs a total of about 12 hours per day, some of which is during the daytime so that we will notice if it is not running.
2. For the most part I have taken over the feeding. I have also shown my husband, repeatedly, how much food should be given the fish and how often they should be fed (overfeeding was a HUGE part of the problem).
3. I wash out the filter baskets every day, or sometimes every other day. Same with netting waste out of the pond.
4. I sort of but not really knew that our Ultima II filter should be backwashed. I had never seen my husband or worker do this, but knew that it was done very occasionally…..like every few months (4-6), usually in conjunction with a water change before a party because my husband wanted the pond to look good. Our pond is overstocked, and a lot of waste is generated, even with a more reasonable level of feeding.
I learned how to backflush the Ultima II. Watched a video online which said to backflush 30 seconds, rinse, repeat. The first time I backflushed…….it took several minutes for the water to become even somewhat clear. So much string algae came out. I emptied several baskets worth which came into the filter basket during the process. Over several days, I probably backflushed 40 times, in the process also doing water changes. This also increased the amount of flow through the filter by about three times (based upon the waterfall and jet flows).
I now backflush once a day or once every other day. It is only after about two weeks of serious backflushing that I’m not getting significant amounts of algae coming out during the backflush. I am still surprised how dark the water can be during every backflush after only 1-2 days, but at least the water becomes clear within 30 seconds. I think that is a sign of our pond being overstocked and even though the fish are now being fed a reasonable amount of food, they generate a lot of waste.
5. Water testing. Ammonia, zero. Nitrites, zero. Ph was fine. However, even after my first round of backflushes and a 30% water change, I did a test on nitrates. The tube immediately turned blood red after just a moment of shaking. Nitrates were well over 160ppm, even after the 30% water change. I did several more substantial water changes. Nitrates are down to 40-60ppm, but I just can’t seem to get it lower than that (straight from the tap is 5ppm). I am planning on substantial water changes every 2 weeks or so.
6. We have a sago palm planted next to our pond. Some of the branches/leaves dipped into the pond, and the fish liked to nibble on them and brush against them, which my husband loved the idea of. I read up on sago palms…..turns out they are considered poisonous to all animals (didn’t read anything specific to Koi, but still….). Toxic to the liver. Trimmed it so there was no way for the fish to nibble.
So, a few weeks later, the pond has never looked better. The water is clear. There is a small amount of carpet algae. No significant string algae.
The sick fish is now quite active. One eye seems fine, but the second eye is cloudy and it seems like the fish can’t see out of it, but it is eating on its own and schooling with the other fish. No fin clamping.
Speaking of the other fish…..they are no longer lethargic. Very energetic. All seem healthy.
So, as a wrap up and a warning to other new Koi enthusiasts or even people who have been casually at it for years without taking it seriously……
1. Backflush your filter regularly.
2. Aeration is very important.
3. Change your UV lights every 12 months.
4. Do not overfeed.
5. Do not overstock.
6. Test your water.
7. Do water changes as needed.
8. Watch your fish for signs of stress and sickness.
9. Be careful of plants surrounding the pond which your fish can feed on.