Pond Water Quality

[Benjamin Boudreaux]

I am writing for advice and help on how to get my water quality right. I did a water test with the fish farm i had purchased my fish with. My water test record showed my PH was 7.5. My total Ammonia was borderline at .72. I added 1 gallon of mircroblift and that fixed that problem. This brings me to the point where i need help and direction. It is my understanding that my total hardness and total alkalinity should be around 105 or above, because it works to keep your PH levels from quick drastic changes. The treatment they recommend was putting 8 - 50Lb bags of what they called "Cal Plus". The problem is the cost of shipping this product cost more than the product itself. I asked the person if i could buy this product locally due to the shipping costs, but he would not tell me what "Cal Plus" was made with. My question is, What Calcium based material can i buy locally to raise total hardness of my water? I have researched this issue. I have read "small scale aquaculture" by Steven Van Gorder. His book is quite informative. He has a section that talks about just water quality. For raising total hardness, he uses calcium chloride. I actually called him and he was very informative. He told me he uses calcium chloride to rise hardness of his water, but he raises his fish in 2,000 Gallon tanks, and only used 3 Lbs of calcium chloride per tank and that i could buy this compound at Swimming Pool stores locally, but it would be expensive to use on a 1/2 acre pond. At this point i am looking for calcium based product to rise my water hardness, that i could find locally for a fair price.

Any help with this problem would be greatly appreciated

[Walt Foreman]

First of all, your pH is right smack in the middle of ideal, so it's unlikely that your alkalinity is exceptionally low.  Secondly, anyone who told you your alkalinity has to be 100 or higher is just trying to sell you a product - 20 ppm is the minimum any reputable pond consultant will recommend, not 100.  

Thirdly, hardness and alkalinity are two separate things.  Hardness can often be raised with ag lime, and in instances where that doesn't work, gypsum; alkalinity is raised with ag lime, but I'm guessing your alkalinity is fine. 

https://srac.tamu.edu/index.cfm/event/getFactSheet/whichfactsheet/112/

[Benjamin Boudreaux]

This is a picture of the Levels of my pond.

i understand that hardness and Alkalinity are different things. I am concerned about my total Alkalinity, Hardness, and pH levels. They are all falling each year and i would like to know the best way to raise them back up

[Walt Foreman]

Your alkalinity is not low, and it annoys me that the hatchery told you it was.  It's twice the level that any respected consultant would tell you is needed.  If you look at that TAMU document I linked to, they list 20 ppm as the cut-off for what would be considered low - and you're at twice that.  Here's another article that cites 20 ppm as an acceptable level:

http://www.noble.org/ag/wildlife/fish-pond-water/

Here's a document from Auburn University, the first (and also generally regarded as the top) degree program in the country in pond management, that also cites 20 ppm as the minimum acceptable - note that they also give 20 ppm of hardness as the minimum acceptable level, and you're at over twice that:

http://www.ag.auburn.edu/fish/international/uganda/docs/catfish%20m...

If you still are concerned, ag lime is pretty inexpensive unless you have a very large pond, which I'm guessing is not the case since one gallon of bacteria made a change evidently - I'm guessing your pond is less than an acre?  The general recommendation for lime per acre is one to three tons; ag lime usually sells for around $100 a ton, so you could add two tons and you would end up with higher alkalinity and likely higher hardness as well.  Your local co-op almost certainly sells ag lime.  

[Benjamin Boudreaux]

thank you for sending me the auburn report,it was very informative.on page 2 under alkalinity it states a total alkalinity of 20/mg/l or more is necessary for good production .the next sentence states a desirable range of total alkalinity for fish culture is between 75 and 200mg/l .i understand this to mean 20mg/l is the minimum needed but 75 to 200mg/l is more optimal.later on  pg.2 under the caption alkalinity,ph,carbon dioxide concentrations it says in water with moderate to high alkalinity (good buffering capacity) and similar hardness levels ph is neutral or slightly basic (7.0-8.3) and does not fluctuate widely. this is my objective for my ph not to fluctuate widely.on the last pageunder the caption effects of ph,alkalinity and hardness on ammonia and metal toxicities it states ideally ,an aquaculture pond should have a ph between 6.5 and 9 as well as moderate to high total alkalinity (75 to 200 mg/l but not less than 20mg/l and a calcium hardness of 100 to 250mg/l.these numbers come from auburn university.my question still stands this report confirms that my original numbers of having 105 for total hardness and 105 for totalalkalinity were in the ballpark,what calcium based product could iuse to raise total hardness.the report also states regular ag lime work in some cases.walt thanks for helping me i am still going thru the learning curve.

[Walt Foreman]

I've never added calcium to a pond, and thus don't know a source or specific product for that.  I would suggest trying lime first, as that typically raises the hardness along with the alkalinity; liming is common practice in pond management, whereas I don't personally know anyone who's ever added calcium to a pond.  Not saying it would hurt - just that there are other things on which your money would be better spent.  Having a good alkalinity level, not hardness, is what regulates the pH.  

Just for reference: there's a lake in North Carolina that is highly acidic - it has a pH of 5.3, barely at a level that's livable for fish.  The lake has a high rate of flow through it, meaning it can't effectively be fertilized, or limed, etc.  The management of the lake has focused on the food chain, with dozens of automatic feeders that feed a custom, very high-protein food twice daily...And it's presently the best big bluegill lake in the world.  Two three-pound bluegill were caught from it in May 2011.

If I were you, I might lime the pond.  But after that, I would focus on the food chain: starting a fertilization regimen as soon as the water gets around sixty degrees - I would guess sometime in February for you - installing a top-quality automatic feeder, ideally one every two acres, and feeding the highest-protein food I could get my hands on.  If you haven't already stocked several types of forage for your bluegill such as crawfish, tadpoles, freshwater clams, and grass shrimp if you have some weedgrowth, I would stock as much of each as I could afford, and then stock a few more.  Assuming this is a pond being managed for big bluegill, I'd make sure I had the best genetics I could source, pure-strain coppernose bluegill, and lots and lots of small largemouth in the pond to keep the bluegill thinned out so they don't overeat their food chain.  If it's a newly-stocked pond, I'd allow no one other than immediate family to fish it for at least a year, and I would implement strict size limits: no bluegill over 9" would ever be kept, to allow the big ones to get even bigger, and I wouldn't keep more than 50 or so per acre per year.  If the pond has had fish in it for a while and is overpopulated with bluegill, that's a whole other ball of wax...