There is also need to identity the probable source(s) of pollution of the pond water. Parameters can be finalized together with the section of treatment/purification  process. The pond water has very low pollution. Colour, pH, Turbidity, TOC/COD, heavy metals etc. are the relevant parameters in case the water is contaminated with industrial effluent. Pond water is contaminated sewage, then microbial parameter is also to be monitored (heavy metals may not be required). If the green color is due to the presence of algae, .COD/TOC and colour measurements are sufficient.      

The parameters to look for depends largely on what you want to use the 'improve pond water' for. Other Parameters to look for in addition to what Dr Kharat has mentioned above could include Total suspended solids (TSS), Total dissolved solids (TDS), Total bacteria and specific bacteria. Heavy metals could be determined if the pond is in an industrial area, and the specific heavy metal(s) to look for depends on the industries in the vicinity. One quick and inexpensive to improve pond water is to add a coagulant. Coagulation will lead to flocculation. That will reduce turbidity and colour especially  if there is a way of removing the flocs.

I have maybe a couple of suggestions, but alot may depend on your interest in the subject, ability to test, desire to collect samples, analyze for algal type, other water quality parameters including pH, alkalinity, temperature, dissolved oxygen variation throughout the day, various nutrient loadings (NPK for example).  But unfortunately, prescribing is often hit or miss for a do it yourself project, and prescribing from arm chair or office may offer ideas, but is seldom very effective.  For expediency, if that is important, consulting with an expert  in the field who has experience with pond algae and water quality considerations may help expedite, and reduce costly testing.  If the water itself is green colored, not from algae, then that would be a different analysis approach.  Of course, in any instance, identify the contributing drainage area for various land uses as they may suggest possible or likely pollution sources.  If this subject is a technical interest, that that justifies more effort in lab testing, time for literature review and study, and still appropriate in this learning process as needed to consult with local experts for review and verification, if nothing else.  There should be quite a few papers and books on this subject available on the internet, but again, the issues you have could be general issues such as too many nutrients from animal wastes, or very specific to the situation such as mining or industry chemical discharges.  I can totally understand as a researcher or scientist, the desire to DIY (do it yourself), and I know the solutions are sometimes difficult, but with enough effort, it is possible.  An old saying that fits is an ounce of prevention is worth a pound of cure.  Sometimes minor adjustments in practices could have prevented this issue, fixing pollution or water quality imbalances are seldom easy.

Dear Arvind Kumar Swarnakar, I agree with our colleagues, so the question is very important and usually the green and blue color in water pond usually related to richness of this water with seaweeds, and might be other reason also related to different chemicals, so the laboratory indicators you need to identify i think are the biological indicators such as BOD, COD, TOC and DO, more over pH, turbidity, salinity (Ec, TDS ) and cations  and Anions, TSS, in addition to different heavy metals in case of recognition of industrial pollution source around. 

Dear Arvind,

(1) Green colored water commonly have high concentrations of chlorophyll-containing algae. Ponds with green lakes are often eutrophic and typically contain more harmful algal blooms. Activities such as farming can increase the green color of pond water through nutrient inputs which act as a fertilizer for algae. The poor water quality conditions can depress dissolved oxygen levels in hot summer months; these conditions can cause fish kills where oxygen drops too low for fish to survive. DO of such water is low.

(2) DO between 3.0-5.0 ppm in ponds is unproductive and for average or good fish production it should be above 5.0 ppm.

(3) Avoidance of over application of fertilizers and organic manure, physical control aquatic plants and also management of phytoplankton biomass, recycling of water and use of aerators. artificial or manual beating of water, avoidance of over stocking of fishes,etc. are recommended for managing DO level of pond water.

Reference: Bhatnagar A and Pooja Devi P (2013) Water quality guidelines for the management of pond fish culture. International Journal of Environmental Sciences 3(6):1980-2009.

I hope this input is interesting and useful to you.

Dear

Dr.D.S.Kharat, Samual baba onoja, William F. Hansen, Ahmad Majar, Dilip kumar Kundu , 

Thanks for showing interest  in my question,

One thing more some fishes are there although DO is low . 

For most warmwater fishes preferred values of dissolved oxygen are above 5 mg/L, however they tolerate also 3-5 mg/L. In my practice I have seen carp ponds with even lesser DO, e.g. during early morning (dyrung the daytime however DO content will rise sharply up to 10 mg/L). Under these conditions they tolerate these values and growth rates were acceptable.

For fish ponds accepted levels of COD with using dichromate method is less than 50 mg/L (Permanganate – 15). You did not state the method used in your case. You can compare your Cod value with these ones and decide. Id water is Green colored you should always include biogenous analyses as well as pH, DO, COD, BOD, Temperature, etc.

Good luck! Bakhtiyor

Dear Arvind,

In pond water of low DO (3.0 ppm), you may get some fish surviving but their growth will be limited. Again few tolerant species of fish may survive under low DO of 3.0 ppm, but for optimum growth and reasonable production, one must maintain DO of pond water at 5.0 ppm or higher.

Thanks Dr. Naveen and Abdulla for your comment.

Dear Arvind,

I absolutely agree with above ideals, then i think u should monitor nutrient index  as Nitrogen (amonia, nitrite...) , phophorus , COD .. because it is source for algae increasing. Colour and odor also need to check, 

And if u have UV machine, check UV 254 absorbances to monitor organic compound rapidly

Dear Thang Long Nguyen

We have UV machine  Please provide the more details of , 'check UV 254 absorbances to monitor organic compound rapidly.'

In pond water, Dissolved Oxygen is 3.0  mg/lit is too  low, it should be exceeded more than  5. mg/lit.    As chemical Oxygen demand value is high and probable  dissolved oxygen may be used in utilising  in COD. Analysis of Biochemical Oxygen Demand is also equally important. 

@24 oC sample is still Green Colour after 7 days, But reset of sample has transparent now ( Pond Water) This is Which kind of algae ? 

 Dear Arvin, uv254 is similar to DOC, you can find it relate to COD by compare it with KHP ( COD standard). you can chose the most suitbale wavelength with your water source. My study use 260 absorbance.  Find it out in attached file

UV absorbance is a method of grasping status of organic contamination of source water or of water quality in the water purification process, utilizing the correlation between the concentration of organic matter in water and absorbance of wavelength of 250 to 260nm.

     Among the indexes that indicate amounts of organic matters in the water are; biochemical oxygen demand (BOD), chemical oxygen demand (COD), consumption of potassium permanganate, total organic carbon (TOC), and so on. BOD and COD are used against organic matters that can be expressed with oxygen consumption, while BOD is used for decomposable substances and COD for biodegradable persistent substances.

 Since existence of such unsaturated bond shows absorption of ultraviolet region, UV absorbance of 260 nm, which is not interfered with by inorganic components (nitric acid, nitrous acid, carbonic acid, etc.), can be a representative index of the amount of organic matters having unsaturated bond, 

     Also, E260/DOC (dissolved organic carbon) ratio is suggested as an index for indicating the component of organic matters. It is possible to evaluate the treatment performance of purification of organic matters by means of the ratio of unsaturated organic matters and molecular weight.      

 Also is your pond big?

Do you check the inlet and outlet? because strong fluent water line can kill algae.

Your 3mg/l DO is too low . So i recommend you should try to use sodium carbonate peroxyhydrate 2Na2CO3.3H2O2 (PCS). H2O2 is a normal oxidizer,it reduces ordor, N-NO2-, CN-, H2S , it can kill simple algae but not damage other plant or animal in pond, it also release oxygen to increase DO .

2 H2O2 => 2 H2O + 2[O]; ([O] + [O] => O2) 

1kg PCS provide 0,6 m3  O2 - DO in pond. 

Na2CO3 increase pH in water pond, so consider to use with pH under 8.3 and low alkalinity. You should do it in hight sunlight and temperature condition to have the best diffusion and aerator.

https://www.youtube.com/watch?v=LbYthEuAj9U may you like it

this is popular application in shrimp pond