Forgot to mention, maybe something like 'Stress Zyme' will help as well. Although not quite as the name suggests as it is more of a bacteria boost agent, so i guess what they mean is cleaner water = less stress.
It sounds like the 2nd Bacteria stage is not sufficient as yet to convert the nitrite to nitrate. The 1st stage which i assume is working converts ammonia to nitrite, so guessing your not showing much as regards ammonia on a test. Likewise the 2nd stage bacteria converts the nitrite to nitrate, so guessing your not showing to much nitrate on tests either.
So it must be the 2nd stage bacteria not fully developed.
Just to clarify these 2 stages ( i can never remember the technical terms for the bacteria)
The 1st stage bacteria can develop very quickly but the 2nd stage is slow in catching up but it will get there. (Think this is the basis of 'New Pond Syndrome')
If possible move most of the fish elswhere until this cycle catches up, maybe just leave a couple of fish in there just to keep the cycle ticking over. Nitrite level will eventually drop.
As Fred says probably best to stop feeding them for a few days (slow the 1st stage down), they will survive.
I would definitley agree about the test strips, as usefull as a choclate teaspoon.
Hi again Trying to upload some piccies but struggling. If and when they appear 2 pics of the Ozone device built around a piece of sewage waste pipe with 1.5" pipe fittings, bottom has a rubber bung to seal and top is left open to atmosphere.
pic of the cabinet where everything lives pic of the homebrew upside down filter Pic of the Nitrite test, i recommend this liquid or tablet test over strips anyday which kinda brings me on to Freds comment. Now and again and i'm not sure why i get these nitrite spikes, the pic shows 2 tests the left 1 being a week ago, the right one taken today (colour in the pic is a bit deceiving) but the left one is about .25 (which is lower than what it was a few days earlier), todays test is practically zero. So i have been looking for another means of controling these nitrite peaks which is where the ozone thing came in.
Still waiting for an ORP device to turn up so i won't install the setup until then so i can get an idea of how well it is working (or not)
Hi Otter It's a Hailea (chinese cheapy one) No ORP built in. Likewise from what i have read about them they can be dangerous to fish if to much Ozone is generated + it can smell bad if to high a setting (something like rotten eggs).
Hopefully have something set up by next weekend if all goes well.
I have a smaller version in my small pond (50 gallon) which seems to work quite well. Is the UV working ? may need to take the screw-on extensions off to see this or maybe the direction ball joint at top most of pump is transparent enough to see.
Also the weather of late may not help, lots of sunshine and lots of rain may/will create an algae spike.
How is the sponge looking in the filter section ? If its covered with green gooey/slime then the UV would appear to be working, if its relatively clean then i would guess something is not right with the UV.
Could try turning the pump down to minimum via the grey ring near top, my reason for this is that the UV doesnt get to see the water for long enough to do the job as the UV quartz section on these pumps is only about 4" long (room for argument here).
Can't think of anything else at present. How big is the pond gallon wise ? Don't see the 2 pics
Hi Clear water and green walls indicate UV is working for the best part.
As Otter mentioned it can be maddening try to get rid of it. It is not a threat to fish and can also be a food supplement, it is for the best part unsightly.
Algae relies on 2 things happening Sunlight and Nitrate. Sunlight if the pond has no shade. Nitrate if overfeeding (waste food).
Try providing some shade (fish will like this as well) and maybe cut down on the food unless you can actually see that it is all being eaten, any leftovers need to be netted after a short period of time.
Something else to try:- Depending on pump/filter outlet arrangment back to the pond. Add a 100/200 micron filter bag and see what it collects after a day or 2. (can find these on ebay as bio bags for biodiesel fuel and are washable, for about ?3 to ?4 )