Why on earth is my pH this high?

[C-Note]

My pH is hovering around 8.2 lately. I know that's not completely out of "normal" range, but I certainly don't want it going any higher, and... it just doesn't make sense considering my pond is at (if not over) stocking capacity. Also, noted today that for the first time I read a Nitrite level just barely above zero, which is enough to concern me since I usually read zero. Here are the pertinents:

Water quality
* Ammonia Level (pond) zero
* Nitrite Level (pond) just barely over 0, but less than .25 ppm (usually right at zero, so this is new)
* Ammonia Level (tap water) zero
* Nitrite Level (tap water) zero
* Ph Level, pond (If possible, KH, GH and chlorine) 8.2
* Ph Level, tap water (If possible, KH, GH and chlorine)
* Brand of test-kit used and whether strips or drops? API Liquid test kit, including high-range pH

Other useful information:
* Water temperature? 60 F
* Pond size and how long has it been running? 1500 gallons, running since Febraury 2015
* What is the name and size of the filter(s)? 2 Laguna Pressure Flo 2100 canisters filters, both with UV
* How often do you change the water and how much? Weekly when vacuuming pond... about around 20%
* How many days ago was the last water change and how much did you change? Saturday, about 20%
* How many fish in the pond and their type? 1 Shubunkin, and 13 small koi (most 5-8", a couple 10-14")
* What kind of water additives or conditioners have you used? I use a basic dechlorinator and try to avoid adding stuff
* What do you feed your fish and how often? Hikari Gold mini pellets, 2-3 times per day (sometimes more when it is very warm out)
* Any new fish added to the pond recently? Yes, 2 5" koi
* Any medications added to the pond? No
* List entire medication/treatment history for fish and pond Did one dose of Prazi early Spring. Treated one koi with Bio-Bandage powder for an ulcer over a month ago
* Any unusual findings on the fish? No
* Any unusual behavior like staying at the bottom, not eating, etc.? No, I account for everyone at mealtimes.

 

[Tula]

I'm not an expert, but know that nitrites come from ammonia , which comes from fish waste. Since you recently added two new fish, , there is more ammonia . Maybe consider reducing the feedings, continue with water changes and can you increase your pond's aeration? Another thought is your filter, but it seems like it would be established enough to break down nitrite to nitrates.

It's good you test regularly and are catching this before it becomes a problem....keep us posted.

 

[CometKeith]

C-Note, It sounds like a nice pond. A couple thoughts... Your pond is still very new. Sometimes it takes a year or more for a pond to settle in and for the ph to go into normal levels. Plants will help lower ph. I don't think 8.2 for a new pond is such a big deal. PH can vary by time of day so you might want to take readings at different times. Also as you know high ph means high alkaline and is the opposite of acid. if there is any water run off or pond water touching high alkaline stone products they can affect the pond's ph. Typically materials like pavers, limestone etc will have high ph's. Portland cement is relatively inert and doesn't give off lime. I hope this helps! CK

 

[DrCase]

A ph of 8.2 is nothing to worry about just keep your Kh up and your ph will hold steady

 

[Dave 54]

only worry above that of 8.5 ph at this level malachite and formalin can become toxic to your fish and thus do them great harm ,
So try to get it back down asap

Dave

 

[C-Note]

Thanks for all the insight. I guess I should mention that one of the 2 filters has been running for over a year now (moved from our old house to the new one), so it has lots of established good bacteria. I'm mostly confused because all of the things going on seem that they would, by nature, lead to a lower pH rather than higher... right?? Adding fish, possibly over-feeding, a hint of nitrite... wouldn't this all associate to more acidic conditions?

I do have plenty of plants. 2 flourishing water lilies currently with over a dozen pads at the surface. Water hyacinth covering nearly 1/8 of the pond surface, plus 2 mini cattails, a Calla Lily, and an iris. The hyacinth of course just started yellowing this week. I know they prefer a pH lower than 7.0 even, but that's not ideal for the fish.

Glad to report no signs of discomfort or odd behavior from the fish thus far. I do monitor them all day via live cam so I can see if they start flashing, jumping, or settling at the bottom becoming lethargic. So far--so good! I'll keep testing the water and see if I can make a very slight adjustment in the right direction.

 

[C-Note]

PONDS ARE SO HARD SOMETIMES!!!!!

Okay. I've vented.

After listing all the above circumstances... today we had 2 koi with one popped eye each. Clearly a sign of stress and water issues. One more is listless, and floating around with his fins clamped. Ugh. Sigh.

Did a large volume water change. Added Stress Coat instead of a basic chlorine remover/water conditioner. Hoping a day or two shows improvement. Otherwise do I do a dose of Prazi??

It was a stressful day. One of our dogs (Tomato) was sick too, so we were simply worrying all day. At least she is now improved!!

 

[CometKeith]

Wow sorry about your sick fish and dog. I didn't see anything about waterfalls or water movement. I feel this always helps to increase it. Also it seems to me you have a high bioload for your size pond. I didn't see the measurement of it but I wonder if there is enough surface area for gas exchange for all the fish you have. Also if you have a plan for when your fish grow because it will make it harder to keep your water quality good over time. That's why us goldfish pondkeepers look like geniuses because it's hard for goldfish to grow enough to create a bioload problems as long as you don't keep adding fish. Also curious if you need to vacuum weekly and if this is stiring up bacteria. Maybe Dave54 can specifically address the eye problems. He is our resident expert on fish diseases on gpf!

 

[C-Note]

Thanks @CometKeith . I guess I did not point out... 2 waterfalls, each 24" wide, as returns from each filter. Plus 3 evenly spaced, large air stones. Plenty of churn and gas exchange. Attached photo shows waterfalls at each end and you can kind of tell where the air stones are in between I think. Yes, it's a heavy fish load. We will either re-home some or DIG more as they grow. I'm hoping for the dig option.

 

[CometKeith]

Wow! your pond and fish are really nice. I would love to have a pond like that right next to our patio. Just curious what are the white spots floating around. Is it foam caused by your waterfall?

 

[C-Note]

Thanks @CometKeith . Yes... Bubbles from the aeration.

 

[CometKeith]

The reason I asked is if there is excessive foam then it is a sign your have a high concentration of dissolved organics. I know you said you regularly vacuum it so it wouldn't make sense that it would be a problem... Overall your pond looks very nice. Good luck with your sick fish.

 

[C-Note]

Updates... my pH is nice in the morning (around 7.4), so that's good, but I don't like such a broad fluctuation to 8.2 by afternoon. I know it's a normal process, but doesn't that much swing each day stress the fish? Rather than trying to make any adjustments to the pH itself, I decided extra shade would be the right course of action. We put up 2 big sail sun shades last night, in hopes of slowing the algal growth that's sucking up all the CO2 by day and raising the pH. Hopefully with less hard-hitting direct sunlight, we can establish a better balance.

The 2 fish that were sick are taking antibiotic food and showing improvement!

 

[Tula]

I'm glad to hear your fish are improving We lost a big tree near our pond last year and miss the afternoon shade, so have been thinking of a sail cloth or umbrella.

 

[CometKeith]

Hey c-note you can also try adding more plants ( or maybe a bog?). I know it's hard with the fact your koi will eat them but having more plants will accomplish everything you want and also will compete with the algae for nutrients.