PH and plant/fish population

[New and dumb guy]

Hello,

I've spent two days reading through all the archived posts about ph levels. I ordered a KH and GH test kit, those didn't come with the pond water test kit I ordered before.

I have a flow through pond, 50 or 55,000 gallons, it's fed by a brook with a waterfall on the other end that connects back into the brook. Nitrate, Phosphate, and Ammonia are all perfect, but the ph is high, probably somewhere between 8.5 and 9.5, hard to tell with the shade of the color on the chart. Based on another thread, i have ordered a digital ph reader as well but it hasn't delivered yet. I've taken the readings several times and it seems pretty constant.

The fish all seem to be healthy and active and don't seem to have any issue with it. i do have a lot of plants, grasses, and weeds growing in the pond. One article online that I found talked about the relationship between carbon dioxide, photosynthesis, and ph, leading me to believe that that the amount of plants I have is too great and/or I don't have have enough fish in the pond to balance out relationship of oxygen/co2 in the water which is what leads to an elevated ph. I didn't see any topics in the ph threads that i searched on this forum that discussed this particular aspect.

I'll be interested to see what my kh is when the test kit arrives, but it feels to me like because I'm at the mercy of whatever whatever is constantly flowing down the brook I have very little chance to actually effect my water on a steady basis by adding baking soda or calcium carbonate or any of the things described in other threads. Seems to me like my only hope would be reducing plants or adding more fish, does anyone have any experience with this aspect or ratio or pond management for pH?

Thanks,
Phil

[fly4koi]

The whole KH buffering issue is because of the closed ecosystem of typical pond, where the fish load is usually high and biofilters are used to process the nitrogen, with periodical backflush and water exchange.
If you have a brook feeding fresh water and, the outflow should carry away the nitrogen, and balance the chemistry automatically.
It is actually the best source of water provided the source is suitable. I suspect you need to use the high range pH test to see the correct pH above 7.

Your plant will also help absorbing ammonia and to some extent, nitrate. The only problem might be rain-water diluting, but since you have pretty ideal situation I wouldn't worry. How many fish do you keep in the pond?

[New and dumb guy]

I have one 12" Sanke, 13 other various koi ranging from 5" to 8", I have 8 or 9 various goldfish that are 5-6", and an unspecified number of "native" blue gill, probably in the 45-50 range that are babies to 5". I have been trying to weed out the blue gills with a fish trap and have gotten 15 of them so far, but they seem to be wising up to it now and I haven't been able to weed out many more.

I am hesitant to add any more koi, as I am hoping that the ones I have will grow big and I don't want to have too many.

Thanks for input and reply.

[New and dumb guy]

I have one 12" koi, I have 13 more that are between 5 and 8". There are 8 or 9 goldfish of various varieties that are 4-5", and large population of 30-40 bluegill that are babies to 4-5". I am methodically trying to remove the bluegill and make it just a koi and goldfish pond but they seem to be growing wise to my fish trap after I nabbed 15 or so of their brethren.

[fly4koi]

One common suggested maximum stock level is 1 koi per 250 gal of water, not sure what else you can do about the bluegills other than mechanically remove them.

[richtoybox]

With a good KH, the pH will be at about 8.3, so with the test kit that you are using, it sounds like you have a great balanced water. The pH is critical only when it is jumping around, which is due to a low KH. If it is always the same, you can't do much better than that.

[New and dumb guy]

Thanks. Other pieces I've read have talked about inches of koi per gallon, so I was unsure how big to expect all my young fish to finish at to accurately figure out what would be ideal. If I can't get the bluegill population removed, I assume you have to include them into the calculation even though they aren't koi. I also am pausing adding more fish at this time because I want to make sure my water quality remains ideal over a long haul, and while I haven't seen a problem so far with predators I want to make sure that won't be a major issue for me over a longer period of time before I invest in more fish. I also figure that over time I'll develop a taste or preference for what varieties I really like and want to be able to add more of whatever that becomes at that time. I also figure that as I become more knowledgeable I will likely want higher quality (more expensive) fish rather than the "pond quality" ones I almost certainly currently have now.

[*Ci*]

Is this a natural pond (mud bottom) or a liner pond? Is there any filtration or just the flow through? Is there anything on the waterfall end that will prevent eggs or fry or larger fish from entering the native waterway?

[New and dumb guy]

I will try and put some videos of my setup on youtube, the videos and pictures I take on my phone are a different file format that I had a hard time uploading. To answer your question, I wish I knew exactly. I have reached out to the previous home owner trying to get some clarity but he must have changed his number. I am almost certain 95% of the pond is a natural mud bottom, but the area that was constructed around the waterfall definitely has a liner. If the whole thing is lined, then there is at least 6" of muck and mud and debris on the bottom of it when I put my waders on and have tried to work on it. I can only get about 1/3 towards the middle of the pond before it is too deep that water level rises above the bib of my waders. When I have some free time next, I'll do some digging closer to the edge of the pond and see if I come to a liner or not. There is no filtration, it's is only flow through. There is nothing on the waterfall end that will prevent anything from escaping other than it is only a very shallow flow over the headstone, and the little brooke/ravine that leads down to the river from the waterfall isn't deep enough to sustain a fish to survive by swimming anywhere. I'll try and get a video on youtube today or tomorrow and post a link.

[New and dumb guy]

Is this a natural pond (mud bottom) or a liner pond? Is there any filtration or just the flow through? Is there anything on the waterfall end that will prevent eggs or fry or larger fish from entering the native waterway?

Here is a link to a youtube video: https://youtu.be/qAJZeYGErew of course looking at it now I wish I had weed whacked and waited for a day when the water was clearer but you'll get the idea.

[fly4koi]

First I'm not familiar with mud pond, but it seems like the pond can use some upkeep to get rid of the debris and excessive plants that's not water lily.
Others with mud pond experience can share more feedback, sometimes too much change can also upset the chemistry balance in the pond.

[Grumpy]

You have a special place! There are a variety of minnow traps for those blue gill, but a sieve net might be the only way...

Thanks for the video