Pond Boss Forums GENERAL QUESTIONS Water chemistry Water Test Report - Adjusting PH?

Got this back in from TX A&M a few mins ago. I haven't had a chance to review in depth but one of the numbers that stuck out to me was the PH. I have seen a contradicting answers to the question on raising and lowering PH in water. Some say the addition of AG lime increases PH and others say adding AG Lime decreases PH (gotta love the google). In my case I may be interested in raising the PH to a number greater than 7.2 or 7.4 on a 1.5 acre body of water with a max depth of 10-11' and an avg water depth of 6-7'.

I would love to hear some feedback if there is something else you guys see in the report or steps I might need to take to adjust the PH.


Thanks,

BD

One other item to note. I overnighted this sample to TX A&M on a Monday. The USPS carrier thought this really needed to be delivered on Thursday the same week. Is it possible that the water sitting for a few extra days may have had an impact on the quality of the water?

I don't see that it's bad. It's "new" water and will change quite a bit in a couple of months when the level is up into the riprap and the eco system begins to form.
Any big changes right now "could" be magnified in the opposite direction with summer coming. It takes some time for the balancing act to occur.
Photosynthesis, and respiration are 2 of the big factors in pH.. You are just into the start gate here.

This is almost the same PH as my water, (6.65) I have not had one pond management person tell me this is anything they would be concerned with

pH swings daily

As luck would have it, the LaMotte test kit arrived today. It's a little different than the API I have been using and I'm a little confused with the results of testing. Here's what I found with testing today.

Sample taken at 2:45PM near the major inflow from the grass waterway leading to the pond.
Sample depth taken in 18" of water.

Water Clarity - Slightly Stained from rain on Sunday Morning

API PH (High test Range) 8.0-8.2?
API PH 7.6+?

LaMotte PH (Wide Range) 7.5?

API KH 4-5 Drops + 80ppm CaCO3
API GH 6 Drops 106.8ppm CaMg
- Seems to line up reasonably to me with the test report I just got back from Texas A&M

Lamotte test kit only had one test for Alkalinity. My reading on this came back at 60ppm. A couple of questions on this.

First, the test kit mentions putting a tablet into the 5ml test tube stirring until dissolved and then adding a solution through the little handheld syringe until the mixture turns purple.
Second, there was a sheet that came with the kit saying that the tablet was replaced with a solution and to add 4 drops to the water sample, stir and then start the test. I'm assuming as no other information was provided that I am still looking for this sample to turn "purple".
I called LaMotte on this. Apparently they ran out of the tablets and substituted the liquid.

My LaMotte sample started off as a darkgreen/blue after the 4 drops were added, and after I started adding the next solution my mixture turned kind of a dark yellow or orange. Last pic of the attached.

Is anybody else using the "new" LaMotte Alkalinity test kit and getting similar stuff?


Seems odd to me that the API Alkalinity and LaMotte tests are so much different on results.

On the API,when pH sample is dark blue that's all it will do, your "high" pH test is good.
pH looks to be 7.8-8, that's good..
Looks like 7.5-8 on the LaMotte.
I wouldn't worry about alkalinity just yet.
Just my experience here, but when pH is over 7.5, alkalinity seems to be acceptable in most cases. I'm sure there are exceptions but this is a brand new pond and there will be some differing numbers (up-down) and when it stabilizes in the first full summer, action can be taken to move or adjust slightly.

Thanks Snipe. I was hoping that I was going to go out and test and see my baseline with TX kind of match up with LaMotte as it's the kit I'll likely use going forward. I just flat don't understand the kit calling from purple and producing yellow or orange with a reading that is quite a bit off of what the university came in at. API looks closer on that part....maybe I'm using both kits for a bit.

Pay attention to EWEST's post above re: the pH swings during a 24 hour time period. Time of day that the sample is taken makes a difference in the pH reading. That could be what you are seeing.

Yes agree with first part but the cause and effect are reversed. Ponds with good alkalinity have stable pH in the 6.5 to 8 swing range - that is the buffering power of good alkalinity at work. See the chart - flatter line. It is the wide swings that cause stress and if extreme then death.

Crazy day today but I did talk with tech support at LaMotte. The yellow/orange color can present itself with PH from what I was told. I'm not sure I understand that but feel better that I didn't do something wrong on the test to get that color instead of the purple they listed. Alkalinity reading this evening around 4:45PM was 78-80 ppm which is getting closer to the baseline testing I had done with TX.
- My thought on this is that the water is still mixing a little from the rain and inflow on Sunday-Tuesday. Typically takes two days for the water to make it off the hill and finish draining into the pond. I didn't retest the PH. Guessing everything is normalizing.

The big take away for anybody else that is using the LaMotte test kit with the new liquid Alkalinity test vs the tablet is that Purple or Yellow are both normal on the color change during the test.

Had a couple of comments on this about testing the watershed soils. Thought I would follow up. Our testing is in the area that we are planning to plant a mini orchard of fruit trees. Anything we do here will likely impact pond water as this is one of the watersheds to the pond.

Sulfur will have a direct impact on PH. Likely use elemental sulfur pellets as it's a slower process. Likely won't have any impact until the soil warms a little as the microbes in the soil have to break it down. If memory serves the microbes aren't really active in cooler temps.


Anything to be concerned with on the Zinc?

One matter of note. The soil sample test shown is for growing trees/plants which is different from ponds. Soil Sulphur is used to increase acidity in the soil. Common to use around concrete foundation houses (high in lime) where you are going to landscape with acid loving plants.

With alkalinity in the 50+ range and adjoining high base soils you probably won't need to add lime.