A noob here with some water questions

[clark kent]

I am in the process of learning how to take care of the pond in the backyard of the house I just bought. I'm in Western NC. The pond is a 1000-gallon pond with only native rocks in it, secured by some mortar. It has a 4000 GPH pump and a Pondmaster UVR 4000 filter, which feeds a large waterfall feature. There are eight small goldfish and a couple of plants in it. To the best of my knowledge, except for some neglect before I bought the house, this pond has been like this for several years. I cleaned it out and got the pump and filter working, and I've given it about two weeks now to stabilize. The water is now quite clear, and the fish appear to be healthy.

Ammonia, nitrites, and nitrates are all below 25 ppm. The pH (checked twice daily) is 8.5-8.6. The kH is less than 53 ppm. The only thing I've added to the pond is about 500 gallons of water from my municipal water system, treated with API tap water conditioner. (I had to remove some water to get to the pump.) That city water has a pH of about 8.4 and a kH of less than 53 ppm. (Using an API master test kit, BTW.)

Everything I've read says that a pH in this range is not ideal, but it is okay as long as it is stable. What concerns me is the low kH. I've also read that without the pH buffering capacity that a higher kH would provide, the pH could drop rapidly under certain conditions. Not good.

Are these conditions possible or likely with this pond?

Should I be concerned about this low kH?

The high pH and low kH of the municipal water are probably the main reasons for the high pH and low kH in the pond. Right?

Should I sweeten the city water I add to the pond with some baking soda or something?

 

[BKHpondcritters]

Hello from another western NC resident! What area are you located in? I'm about 20 miles east of Boone.

As far as your water parameters go, I'm far from an expert, but it's my understanding that fish can adjust to a pretty wide range of conditions as long as they're stable. Your concern about pH swings due to the low kH aren't unfounded. I'm on a private well, but it's also very soft (LOW kH) with a neutral pH (7 - 7.5) but my pond generally maintains a pH of 8 - 8.5. I do keep an eye on my kH (especially after a prolonged period of heavy rain, such as we've experienced recently) and add baking soda to the pond if it tests low. (1 C per 1000 gals, mixed into a bucket of pond water & added daily, until tested kH levels are around 100+)

I know that adding crushed oyster shells is another recommended way to boost kH, but when your water runs alkaline my understanding is that's a slower & less effective way (water must be acidic to dissolve them)

 

[longhair]

I am in Western NC too! About 30 miles from Boone. Nice to see local folks on here.

 

[WaterGardener]

Your pH is not a problem. As long as it is stable, the fish will be fine. Your KH could be an issue. The nitrogen cycle is ongoing 24/7, 365 days a year. It creates acid, so that eats up your alkalinity (KH). It is something that needs to be boosted every now and then, so you need to keep an eye on it. Yours is lower than I like to see. I consider 100 a minimum, and if you have a pressure filter like I do, I feel that 200 is better. It seems that pressure filters work best with a higher KH.

I use baking soda to keep my KH at that level. I try to keep up with it, and I boost it before we expect to have any heavy rain. The rain along the east coast tends to be acidic and it can drop the KH level pretty quickly if you get a lot, so it's a good idea to raise it before you expect those rains.

It sounds like you are doing a great job with your pond and it's good to know you are the research to keep it healthy. Enjoy it.

 

[clark kent]

We've had a few warm dry days here, and the level of the pond dropped some from evaporation, so I added a cup of Arm & Hammer to a hundred gallons of water and added it to the pond. The kH is now up to about 141. The pH was unchanged, still 8.5 - 8.6. I think I can live with that for now. In the future, I'm going to always add some baking soda to any water I add to the pond, to get its kH up to 141 or so.

I'm going to be watching the kH and pH closely for changes and try to note what causes them.

Thanks for the help!

BTW, I'm about 15 miles from the Ga and Tn state lines, and two hours from anywhere.