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Research Journal of the University of Ruhuna, Sri Lanka- Rohana 13, 2021
Changes of Water Quality Parameters

There were no significant differences among treatments (p<0.05) in water quality

parameters except pH. The highest conductivity 114.695±2.4638 (µs/cm), nitrate

0.4043±0.0287 (µg/L), ortho-phosphate 48.952±2.8970 (µg/L) and the lowest mean
DO 4.1638±0.4078 (mg/L) were recorded from control tanks. The lowest BOD5

0.6465±0.0813 (mg/L) was recorded from T3 tanks (Table 06).

Table 06: Water Quality Parameters in Experimental Tanks.

Treatment
Parameter
T1 T2 T3 C
*
a
b
a
a
pH 7.09 ± 0.07 7.10 ± 0.06 7.11 ± .08 6.78 ± .03
Conductivity (μs/cm) 110.51 ±0 .12 111.08 ± 2.15 107.53 ± 1.88 114.69 ± 2.46
Temperature ( C) 28.02 ± 0.11 27.99 ± 0.12 28.06± 0.11 27.98 ± 0.12
o
DO (mg/L) 4.62± 0.37 4.84 ± 0.39 4.84 ± 0.42 4.16 ± 0.40
BOD5 (mg/L) 0.69± 0.06 0.73± 0.10 0.64± 0.08 0.79± 0.08
Nitrate (μg/L)
0.39± 0.03 0.38 ± 0.03 0.37± 0.03 0.40 ± 0.02
Ortho phosphate
(μg/L) 46.38± 2.82 46.19 ± 3.20 43.23± 2.78 48.95 ± 0.89

* Indicates significantly different water quality parameters among different treatments at p < 0.05.
Similar letters indicate no significantly different among food categories within the fish species.

Discussion

The study has mainly focused on the effect of diets containing medicinal plant
ingredients (Sesbania grandiflora, Aegle marmelos and Allium sativum), on the

growth performance of red tilapia cultured in indoor fiberglass tanks. Also, water

quality parameters were assessed to determine if there is any effect on water quality
due to medicinal plant ingredients containing fish diets.

A higher condition factor means that the fish has attained a better condition.

Condition factor of fish can be affected by a number of factors such as stress, sex,

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