EDITED TO ADD PHOTO
Hello All-
I am in some desperate need of help. I have contacted my pond professional but he is not able to get here until later this week and my koi are dying by the day!!! Here is the situation:
In 2017, my husband and I purchased and restored a large ~90,000 gallon oval pond that was adjacent to our property. We used a professional company to do all the restoration and to get the pond water to the perfect levels for fish. This is a spring-fed pond, so we had to be careful to include the water quality of the spring water in our assessment of how to best balance the water quality. They finished their work in November 2017 and we added roughly 125 medium-sized koi to the pond in May of 2018 (~5-7"). In June of 2018, this same pond company called to ask if we would be willing to take an additional 30 koi from a customer of theirs who was taking down her pond (due to her age, she did not feel she could care for her pond anymore). We gladly took them and, much to our surprise, these fish were HUGE - some measuring 2-2.5 feet in length! We were told that these fish were all more than 20 years old and one was nearly 30 years old!
We took very good care of our pond and our fish. We had monthly maintenance performed by the pond company and checked the water every week or so ourselves, just to make sure everything still looked good. We did not lose a SINGLE fish since May of 2018. That is, until 1/22/19. On the 22nd, I noticed one of the medium fish was floating. I did not think much of it because we just had a deep freeze the previous two days and I figured it just got too cold for that fish. I did not notice anything else strange. The next day, I found another medium fish floating and I was concerned and took a sample of water to the fish store to be tested (since I use strips, and they are not too reliable). The results came back startling - the water was highly acidic (pH was 6.3!). Also, Ammonia was high (.25). Also, I noticed the fish were hanging out under the water fall and the water fountain, which they NEVER did before.
I called my pond expert and, based on the water readings I gave him, he told me to put in two bottles of concentrated ammonia remover (he had left us some bottles for emergencies) and to add 4 gallons of diluted baking soda to the pond, which we did. The next day, another fish died - but this time one of the big ones. I was heartbroken. Our pond guy had us take a water sample to a local store he trusts and they told us to add a gallon of cold water beneficial bacteria and one bottle of Vanish Plus dechlorinator Plus Stress Reducer and 4 more pounds of baking soda, which we did (our pond guy agreed with this). We lost two more medium fish the next day. We have continued to add diluted baking soda (4lbs) daily and have seen some improvement in the water quality, but still, the fish keep dying (lost 2 more today, including one of the big fish). Is there anything I can do to save the fish that start to struggle and anything I can do to prevent other fish from struggling. I used to enjoy going down to the pond everyday and now I just dread what I will see when I get there!!
I am beside myself trying to help these fish and begging my pond guy to come sooner (he is on a job quite a distance away from my house at the moment). He told me to keep measuring and testing the water and to keep adding the baking soda daily to get that pH up to 7.5, very slowly. If anyone has ideas or suggestions for what I might try, please share. Here is some of the data on the water quality and the pond itself:
Current pH: ~6.7 using drops and 7.0 using a test strip. Starting pH: 6.3 using a professional digital meter
Current Ammonia: ~.10 using drops. Starting Ammonia: .25 using drops
Current Nitrite: 0 using drops and .5 using a test strip. Starting Nitrite: 0
Current Phosphate: .5 using drops. Starting Phosphate: .25 using drops
Current GH: 180 using strip. Starting GH: 180 using strip
Current KH: 50 using strip. Starting KH: 0 using strip
Current Nitrate: ~30 using strip. Starting Nitrate: ~20 using strip
* the size and stocking density of your pond: The pond holds about 90-95,000 gallons of water. I don't know the dimensions, but it is oval shaped and 3 feet deep at one end, with a drop to 8 feet at the other (where we have built a large cave for the fish to hide)
* the type of filtration you have: We have 6 jets on the top surface of the pond sending water clockwise and 6 jets at the bottom of the pond sending water counterclockwise. We also have a waterfall and a water fountain that run 24/7
* your maintenance routine: We have a professional company come out monthly for routine maintenance from March through November. In November, they 'shut down' the pond for to winterize it and got most of the leaves out. My husband and I also skim the pond to remove leaves every few days throughout the year.
* the last time you performed maintenance: Full blown maintenance was the 2nd week in November (and everything was fine). I have added chemicals to the pond as specified above.
* They also need to your water parameters, including the temperature: The last I checked a few days ago, the water temperature was 39 degrees.
* The last time you added a new fish: we have not added fish since May of 2018
THANK YOU!!!!!