Pond Water Quality (the basics) Frank Henning UGA Watershed Extension Agent

To a great extent water quality determines the success or failure of a fish operation

EatEat BreatheBreathe Excrete wastesExcrete wastes ReproduceReproduce Take in and lose saltsTake in and lose salts Fish live in water

Water Quality Factors Oxygen/CO 2 Alkalinity, Hardness & pH Sediment Nutrients (NH 3 and P) Temperature

Dissolved Oxygen ImportanceImportance –highest cause of mortality Safe levelsSafe levels –greater than 5 mg/L Dense bloom, bloom die-offDense bloom, bloom die-off herbicide app. & turnover herbicide app. & turnover

Daily O 2, CO 2 Cycles

DO Management Avoid Overfeeding Maintain Proper Densities Avoid Over-fertilization Intelligent Weed Control Monitor Inflow Quality

Outlet Design

Signs of Low DO Fish not eatingFish not eating Piping & GaspingPiping & Gasping Groups of Fish at InflowGroups of Fish at Inflow Poor GrowthPoor Growth Frequent Disease/Parasite OutbreaksFrequent Disease/Parasite Outbreaks

pm10 pm5 am Measured values Projected values mg/l Projected Dissolved Oxygen Levels Lethal

Problem Suspected Monitor DO Provide Aeration & Circulation

Temperature Effects – –metabolic rate doubles for every 18 o F increase – –Influences spawning – –Influences growth Water Density – 39 o F – –Turn- over Fish Categories – coldwater – coolwater - warmwater

pH Measure of the hydrogenMeasure of the hydrogen ion concentration ion concentration 1-14 scale1-14 scale –less than 7 acidic –greater than 7 basic Safe rangeSafe range –

Hardness Hardness if the measure of divalent cationsHardness if the measure of divalent cations –calcium –magnesium Hardness is used as an indicator of alkalinity but hardness is not a measure of alkalinityHardness is used as an indicator of alkalinity but hardness is not a measure of alkalinity –magnesium or calcium sulfate increases hardness but has no affect on alkalinity Recommended hardness levels > 20 ppmRecommended hardness levels > 20 ppm

Alkalinity Alkalinity is the capacity of water to buffer against wide pH swingsAlkalinity is the capacity of water to buffer against wide pH swings Acceptable range mg/LAcceptable range mg/L

Liming Ponds Total Alkalinity > 20 ppmTotal Alkalinity > 20 ppm Agricultural LimeAgricultural Lime ~ every 2 – 4 years ~ every 2 – 4 years Broadcast Over the Broadcast Over the Entire Pond Surface Entire Pond Surface Professional LimingProfessional Liming Barges on Large Ponds Barges on Large Ponds

Total Alkalinity Lime/Surface Area 12 mg/l1-2 ton mg/l1 ton mg/l1/2 ton 25 mg/l or moreNone Guidelines for Application of Lime in Ponds

Proper Fertilization 5-10 apps per year Start in February Time apps using secchi disk Shade out weeds

Fertilization Supplements the Food Chain More Fish - Not Bigger Fish Multiplies the Base of the Food Chain Increases Carrying Capacity 4X

Using the Secchi Disk Professional Disk $25 Measures visibility Measure frequently Pie pan, 5 gal bucket lid w/ weight.

Granular Fertilizer Applications Usually applied usingUsually applied using a platform a platform Upper end of pondUpper end of pond

Liquid Fertilizer Applications Tip # 1 - Dilute the fertilizer with water. Tip # 2 - Use small bilge pump. Tip # 3 - Pump or pour into prop wash. Tip # 4 - Cover the entire pond.

Water Soluble Fertilizer New trend Easy to apply Fast results

Water plants Food Excess food Fishes Peptides Amino acids Urine Urea Ammonia (NH ) Algae Nitrate (NO ) Nitrite (NO ) Feces The Nitrogen Cycle

Management for N Problems Reduce DensitiesReduce Densities Avoid OverfeedingAvoid Overfeeding Water ChangesWater Changes AerationAeration SaltSalt

Clearing Muddy Ponds Step # 1 - Find the Cause Undesirable Species Undesirable Species Poor Watershed Management Poor Watershed Management Undesirable Water Source Undesirable Water Source Step # 2 - Evaluate Solutions Total Renovation of Population Total Renovation of Population Watershed Vegetation Watershed Vegetation Chemical Alternatives Chemical Alternatives Step # 3 - Implement Management Plan Establish vegetation in the watershed Establish vegetation in the watershed Lime pond, lb Gypsum, Alum

Phosphorus Limiting nutrient Animal waste Monitor nutrient input >0.1 ppm (0.05 ppm)

Test Kits Turbidity (Secci) DO Ammonia pH Temp Alkalinity Hardness

Lab Analysis (UGA Extension) Alkalinity Hardness Phosphorus ASK UGA1

More Information

Hydrogen Sulfide SourceSource –well water –inadequate filtration shift from aerobic toshift from aerobic to anaerobic breakdown anaerobic breakdown of wastes of wastes RemovalRemoval –intense aeration

Chloride & Salinity Ammonia &/or Osmotic StressAmmonia &/or Osmotic Stress Add Salt to 0-3 ppt chloride optimal for freshwater fishesAdd Salt to 0-3 ppt chloride optimal for freshwater fishes Plain non-iodized saltPlain non-iodized salt Some culture species require more or lessSome culture species require more or less