Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants How to get rid of FA before fertilizing

870, I was in a Petsmart store looking to buy an aquarium. The sales rep said u could bring by a water sample anytime and they would ck the water for u. Not sure what all they ck but might be easy to do if u have a petco or petsmart store nearby.

Tracy

Tracy,
That's good info...got a Petsmart near my house. I will bring a sample by tomorrow.
Charlie

let us know how that works out. I wondered if they ck alkalinities? I might tell them the water came from my aquarium

Tracy

I ended up killing off the FA with Cutrine Granules. My water analysis came in today. Based off of the results, what do you guys suggest that i do? Do I need to add anything. My water is clear as a bathtub and i definately want an algae bloom.

Mine is too, but that's after everyone has bathed and we can't find the baby!
(sorry, that's due to my envy of those with clear water )

Consider this a bump as I can't help with your test results but the experts should be here soon.

pH target is 7.0-7.5 Your reading could be high, depending on what time of day the sample was taken.

sample was taken about an hour before dark

I would do something to address the high pH issue then. pH is highest during the middle of the daylight hours.

What should i do to lower the ph?

870,

FWIW I would not worry about it or do anything. Your PH and alkalinity are in line with mine (my alkalinity is closer to 250 -300), (I think) Cecil's and I'm sure a lot of other folks. My pond is still relatively new but I've had a good bloom the past two summers and my fish appear to be healthy. With a high alkalinity number, I'm not sure what you could do to provide a long term adjustment to the PH anyway and might just end up creating a problem.

Just my 1 cent - I am not a pro

Good discussion, I am interested to see what other folks have to say from their experiences.

Bill D, if his pH was 8.28 in the evening, what would it be mid-day when it is at it's highest reading in the pond?

In my pond, the PH varies very little with time of day. I suspect the high alkalinity acts as a buffer that keeps PH pretty stable but I'm not a chemist. Hopefully, some other folks with experience with this kind of water will chime in.

Bill, remember that the key component to growing fish in a pond is good water quality. Fish don't grow as well when they are stressed, and that "stress" can be a myriad of things. Predators, turbidity, water chemistry, etc. Fish blood has an average pH of 7.4. The closer that the water quality mimics that pH the less stress the fish will be under.

If I was measuring pH in my pond in early morning or late afternoon, with alkalinity in the 150-200+ range, I would want my pH to be in the 7.0 - 7.4 range, but closer to 7.0. That way the daily pH swings will be closer to matching the fish's' pH. To adjust the pH in 870's pond, I would carefully add alum and continually test the pH while doing so. Why alum? It will do two things, drop the pH and bind up excess P that is in the pond. Binding up the excess P will help reduce FA production, which is a problem in his pond.

Interesting stuff...I always think of things a little upside down I guess so, of course, I have lots of questions.

I agree there is an optimum PH. Isn't there an "ok" range? My PH is 8.3 or 4 and the fish seem fine. How can I tell the PH is stressing them and my pond is in trouble? I suspect you are correct you could pull that PH down with Alum but won't it just go back up over time as the Alum gets tied up and the watershed provides more "High" PH water? Would you possible need to add Alum every once and a while to keep the PH in the optimum range? Any concern about potentially putting so much Alum in the pond over time?

Very interesting stuff so been doing some digging.... Found this...

Bluegills can tolerate a pH range of 4.0 to 10.3 (Trama 1954; Ultsch 1978) but pH levels at these extremes have caused at last partial kills (Calabrese 1969). Optimal levels are 6.5-8.5 based on Stroud's (1967) criteria for freshwater fish.

largemouth bass require a pH between 5 and 10 for successful reproduction (Swingle 1956; Buck and Thoits 1970). Using Stroud's (1967) criteria for freshwater fish, optimal pH range is 6.5-8.5. largemouth bass can tolerate short term exposures to pH levels of 3.9 and 10.5 (Calabrese 1969).

Supports the thought that 7 to 7.5 is ideal but straying a little is still ok, at least according to these guys.

My ph is 8.4 to 8.5 in my ponds. It doesn't vary during the day due to the immensely high buffer of 350 mg/l of alkalinty. I have a heck of a time dropping the ph in my swim spa that uses the same water. As soon as I get the ph down in the range that works the best for chlorination with muriatic acid it bounces back.

I have no problem growing fast growing large fish in my high ph, high alkalinity, very hard water.

I'd post pics but think everyone has seen them.

Largest BG so far: 1lb. 8. 1/2 oz.
Largest YP: 2 lbs. 13 oz.
Largest Brook Trout: 6 lbs. 10 oz.
Largest Brown Trout: 12 lbs. +
Largest Rainbow Trout: 9 lbs. 9 oz.
Largest Smallmouth 3 lbs. ? *
Larges Largemouth 6 lbs. *

* Didn't keep them long enough to grow them very large.

I wouldn't be concerned if pH levels were checked mid-day and found to be in the range that Cecil is reporting. But, if they were higher than that, I would.

Excessive ph later in the day is usually indicative of too much weed growth and low alkalinity.

I have not tested my ph since the pond was in its first year, but I know I am having the same problems with the FA and not having a good enough planktonic algae bloom to keep it down.

Seems like the water is clear early in the season and the FA gets the jump on a planktonic algae bloom.

Treated the outside 3-5' of the pond with Cutrine granuals then later sprayed a small amount of the Cutrine liquid around the outside foot. Seems to have knocked it back pretty well at least temporarily. Trying to use as little as possible and still get shore line control so I don't kill all the algae in the entire pond. Is that an unrealistic goal?

But last year the FA ended up covering out to a 4 or 5' depth and entailed a significant portion of the pond area. So I am trying some pond dye to see if that helps. Started out with 2 quarts of Black DyeMond pond dye (a quart of this concentrate is supposed to equal a gallon of regular pond dye) and saw what it looked like. Put two more quarts in a day later after the first had dispersed. Recommended rate is 1-2 quarts per acre for an average 4-6' depth pond so I would say I am at the current lower end at 1 qt since my pond is three acres. It appears to have helped keep the light from penetrating so deep, but we will see. Will wait a few days and see if it appears to be helping.

I don't like the idea of using the dye because as I understand it will also tend to inhibit a planktonic algae bloom, which is wanted to feed the natural food chain. The Cutrine also kills the planktonic algae so it also reduces pond productivity. So both seem to have negative aspects to using them.

Seems it is darned if you do, and darned if you don't try to control the FA.

From my experience last year, the FA harbors lots of beneficial insects for the fish to eat. I don't mind a little of it because our pond is not kept as a manicured urban estate. But I do not like the huge floating globs that make fishing difficult and the pond unsightly.

We will see how the spot treatment with Cutrine in combination with dye works. I've avoided fertilizing because I think my problem is already excessive nutrients and I don't want to add to the overall problem. I feed 3-4# feed daily per acre and that is already adding a lot of fertility.

Along that same line of thought, here is an interesting read from SRAC on causes of high PH in ponds and ways to manage it.

http://www2.ca.uky.edu/wkrec/High-pH-Ponds.pdf

snrub, I don't think that you need to worry much about planktonic algae if you are feeding.

Ok, thanks for that info. I'm just supplemental feeding, but I suppose there are still lots of natural food anyway to fill the gap. Hopefully.