We overwintered 15-16 fish successfully again. We gave away 5 younger ones last month and got two new ones from a reputable fish store.

On 7/9 fish stopped eating, and acting very lethargic. Foam at waterfall. On 7/11 I did some reading here, and did a 1/4 water change, with extra amquel.

On Saturday 7/12, I bought new test kits. Mine had gotten really old and I stopped using them since we had had no problems. I PH was 7 and ammonia 0. I did another 1/4 water change. later that day 2 of the oldest biggest fish were dead, and a few of this year's babies also were dead. Rest still acting lethargic and not acting hungry. I went back to store and got Tetrapond pond treatment at their recommendaton it might be parasites. Treated pond. Sunday was another 1/4 water change. No more deaths, but nothing seems to be improving either.

two side notes: We had not had much rain, but had heavy downpours 3x last week. We are also having really smelly water right now from the fine city of Minneapolis. The paper reports the water department is adding chemicals to try and improve taste and kill the algae causing the smell/taste. I had put about 20 gallons of tap water (with amquel) in to top off the pond on 7/6.

Questions: What else should I try or do?

How long will it take fish to perk back up if it was either water quality issue or parasites?

Other recommendations? tests? We are so sad to see the fish this way.

Keep in mind that most fish have low levels of parasites all the time, but their healthy immune systems keep them in check. During times of stress (such as moving to a new home), the fish use their system resources to overcome the stress, and let the immune system slack off. this allows any low levels of parasites to quickly grow to the point of causing problems.

But lets concentrate on water first......

Tested with the "quick dip" strips and KH is coming up between "moderate and ideal"

preformed pond, just normal amount of debris in bottom. I cleaned as I normally do over the weekend, no huge buildups.

350gph pump with pondmaster filter, been changing every 1-2 days. Again, just like normal.

using Amquel+ for years, as water treatment when adding water, not as pond additive. I did add extra on Friday when I thought it could be ammonia spiking.

also bought and added aquarium salt yesterday 1/2 recommended dose, since I have never used these before

One more fish dead this morning, first since saturday. Red around gills.

I stopped the water changes on Sunday after third time as the wife thought I would be losing all the good water and treatments. Should I start again?

The tetra product you used is a little "iffy". The active ingrediant is Quinine-hydrochloride, which is dangerous and not quite as effective against many parasite. Not knowing what the parasite is creates another problem. there is not one single parasite treatment that gets them all. Dimilin takes care of the larger parasites (fish lice and anchor worms but I don't think this is what you are dealing with). Prazi or fluke tabs takes care of skin and gill flukes, and A formalin/malachite green product such as ProformC will take care of the rest of them such as ich and costia.

So here's my suggestion. First...get an aerator in there to help them breath. Do some water changes to get the salt levels down to less than .1% since many parasite treatments are not compatible with salt, and treat them with Prazi or fluke tabs for flukes and proformC or a similar malachite green/formalin product for the rest of the parasites. They will need to be treated for a total of 10 days because the life cycle of ich must be considered and there is only a tiny window of time during their life cycle that they can be killed. Follow the dosing on the bottle and even if the bottle says one dose is all that's required, do multiple doses anyway. Retreating with ProformC every 3 days with a 25% water change before each new treatment will be fine.

When you have a small pond and a large number of fish it is harder to maintain good levels and you could be putting a large bio-load on your filter and plants. A large bio-load will also cause your water to foam at the waterfall. Go to Koivet.com and look at some of the articles they have on this killer. Look in search bar under nitrate/nitrite poisoning.

clarify for me if I should treat 3x in 3 days, or once every 3 days?

But thanks for the excellent reference!

thanks for all the help (belatedly).

Anyway, fish in a new home need some time to get used to it. Hiding for a few days is normal. Soon they will come a running for food again!

Next, if you didn't wash the dirt out of the gravel yeah it can make the water dirty. Fish don't seem to mind this (yeah, but we do). It should clear itself either by getting trapped in the filter or just settling out. Most things you add to clear it are bad for the fish.

Finally, but most importantly, in revamping your pond you may well have killed off the bacteria living there that is processing the ammonia fish waste (very bad stuff) into nitrite (also bad stuff) into nitrate (not so bad in low levels) that plants use as food. This bacteria grows naturally but slowly. Keep an eye on your ammonia levels and be prepared to do water changes to keep it down until your bacterial is back.

If my water were murky and my fish unhappy, I would start with a 50% water change.