Sorry to hear about the loss of the friendly pet fish.
as to the dechlorinator....
Ya do what ya gotta do sometimes. Hope The survivor makes it for you, if it does you know it's a tough fish.
Not much more to do now but maybe 1-2 ppt of salt to help the survivor past the nitrite spike and go through re-cycling the pond.
BEFORE NEXT TIME
Get one of those hose tap timers that will automatically shut off the hose after some particular amount of time or amount of gallons of water so the next time the hose is left on it will shut it's self off.
Get a stock tank float valve so your pond can be automatically topped up as the water level drops so it will only get a small amount of top up water at any one time (barring any major leaks somewhere) which might not let you monitor the water usage very well but it does make for consistent top ups. I use those plastic stock tank float valves from Tractor supply and get a hose to PVC adapter and plumb it in with ridged pvc pipe to support it at the level I want instead of using the metal brackets that come with it.
Sorry for your loss. I too have lost fish due to stupid mistakes. TC'c advice on a hose timer is a VERY good one. I use one too and now completely avoid any over watering issues all together. Mine works by a set number of gallons and is very easy to use.
If you are getting nitrites then you did not kill all the bacteria. The process is kick starting again. If you have nitrites it is because the bacteria Nitrosomonas(converts ammonia to nitrite) grows faster than nitrobacter(converts nitrite to nitrate).It takes a few extra days for nitrobacter to bloom and knock down the nitrite. We typically see this same thing happen when starting up raft or DWC systems. Large volumes of water will hold lots of bacteria which will allow you an advantage to getting your balance again. I am usually able to get a raft system through the nitrite spike and producing nitrates in about 7 days(when seeding the new system from an existing one). I bet that if you wait a few more days your pond may be back in balance. Hopefully the nitrite spike will not harm your remaining fish!
Thanks guys for the advice and kind words. TC I went out over the weekend and bought pond salt and a hose timer, I have considered the float valve thing for a while and am going to look into it a little more before this ever happens again. My last koi pond was bigger and a little more forgiving of water mistakes. Chris I am hoping there is some bacteria left that will help rejuvenate the system quickly, as of last night the water was very green but I have not tested it since Saturday I will recheck it this evening. Now my last fish is very skittish and I think once everything balances out I will have to get him a friend. He was always swimming next to the bigger fish like a sidekick and now seems a little lost. I am very grateful that I have found this great community and all your help thanks a bunch you two!!!
Very interesting, I looked into this product and may contact the company for more information and local sources. Thanks a bunch!
Ellen Roelofs said:
You could dose with a nitrifying bacteria culture to get things going again... I got mine at our local grow shop, it's called Bio-Cat. Doses 15,000 gallons for 11.95. This was a more affordable source than the pet store.