PH Low in new pond

[mowgli789]

Hi,

I have recently dug my own pond. It is 2 fairly large ponds, one running into the other. Total size of both ponds is about 7000ltrs. There is a pump in the bottom pond which sends the water to a filter, and then back into the top pond.

After making it we had it running for about 5-6 weeks and kept testing it, and everything looked fine. A couple of weeks ago we bought some goldfish and added them to the bigger bottom pond. Fish are fine and seemingly healthy, although spend most of their time hiding.

A week or so ago I tested again to check it was all ok, and I noticed the PH had dropped. I checked a few days later and it had dropped further. I bought a digital PH tester and it looks like it has dropped to about 6.

I have already treated it with a blagdon PH adjuster, but it did naff all and was very expensive.

Does anyone have any suggestions as to how to best get the PH back to where it should be?

I should point out also, I think the reason it has dropped it because we are in a very acidic soil where we are in the south of the UK, and we also haven't had any rain in about 2 months. So I think the PH has dropped because where we are watering the plants around the pond and soil is probably splashing into the pond. This is my best guess, but open to other ideas too.

Thanks

 

[WaterGardener]

You have had a pH crash and the water is very acidic. It can kill your fish and will make it difficult for your beneficial bacteria to get established.

PH naturally drops over time. The nitrogen cycle creates acid so it is an ongoing process.

You don't need to buy expensive products to raise the pH. Plain old baking soda works well and is what most ponders use. It can be bought very inexpensively in large amounts at big box stores if you have those nearby.

Don't try to raise the pH quickly. Do it slowly so as not to stress the fish, no more than 0.2 points per day. Raise it over several days, not hours.

The reason your pH is dropping is that you don't have adequate KH (alkalinity) in the water. KH buffers the acid and keeps pH stable. But KH, like pH , falls over time so it needs to be boosted every now and then.

A KH test kit is essential in my book. If there is enough KH, there is no worry about pH. Stable pH is much more important than having a certain level of pH. A good level for KH is 100 ppm, but more than that is not a problem. I keep my pond at around 200 or more. More is not harmful.

At that level of KH the pH will be around 8.2 or so. That's fine and as long as you raise the pH gradually, the fish won't have any problems with it. You will need a high range pH kit to check it.

Congratulations on your new pond.

 

[sissy]

I always go natural baking soda arm and hammer ,,crushed oyster shells they sell in farm stores for chickens and peroxide . I some times get free oyster shells and crush them . . You need a test kit that tests for everything . I use liquid API test kit that you can get at most pets stores or online

 

[Lisak1]

Have you tested your source water? If you haven’t had rain I’m assuming you’ve had to top off the pond.

 

[mowgli789]

Thanks for the responses guys.

I have total testing kit. That was where I noticed the PH dropping. I then bought a digital PH tester to get a more accurate level. It's currently showing 7, so appears to have come back a bit.

I will check the KH level, but the last time I checked it it was in the middle of where it is meant to be. Again I'm wondering if the drop was caused by acidic soil getting in the water. I have been much more careful with this recently, and it looks to have recovered a little, maybe with the expensive PH raiser.

I will top up the KH and keep a close eye on it.

Thanks all

 

[sissy]

could something be washing into your poand when it rains . Even worse spray from other peoples fertilizer methods . I have a neighbor that has a company come in to spray his yard

 

[sissy]

By the way the horse farm near me sprays some kind of bug spray for these huge white horses they raise . But they do warn me when they are going to spray that field . I can stand under the horses and they are not even a year old . When they run yu can feel the vibration