Ultraviolet sterilization technology directly destroys the DNA replication ability of algal spores through radiation with a wavelength of 253.7nm. Experiments have proved that it can inhibit the proliferation of plankton by 80%. For example, the average biological concentration of the green algae phylum decreased by 50% (the chlorophyll a content dropped from 25µg/L to 12.5µg/L), and the cell division rate of diatoms decreased by 60% (from 1.2 divisions per hour to 0.48 divisions per hour). A study published in the Journal of Aquatic Engineering in 2023 shows that when a UV Filter with a power of 24 watts was operated in 100 liters of water for two consecutive weeks, the wet weight of algal biomass decreased from 180mg/m³ to 45mg/m³, and the turbidity NTU value simultaneously dropped by 70%, effectively delaying the formation cycle of Chlorella on glass walls (extending from 3 days to 9 days).
For the control of blue-green algae (such as microcystis), the inactivation efficiency of the UV equipment reaches more than 92% (when the irradiation dose is 30,000 µW·s/cm²). The practical case of the National Aquarium of Singapore has confirmed that the UV Filter operates for 8 hours a day, keeping the concentration of the blue-green algae toxin Microcystin-LR at 0.3ppb (lower than the 1ppb safety limit set by the World Health Organization), and reducing the frequency of algal blooms from an average of 1.5 times per month to 0.2 times. The technical principle lies in destroying the airbag structure of algal cells, resulting in a 40% increase in the sedimentation rate (from 0.8mm/h to 1.12mm/h), and eventually being captured by the physical filtration system.
Environmental impact data show that UV algae control can maintain the dissolved oxygen stable at 5.8±0.3mg/L (the fluctuation range of the untreated group was 3.2-8.1mg/L), avoiding the increase in fish mortality caused by nocturnal hypoxia (with the incidence rate reduced by 15 percentage points). Tests conducted by the Eheim laboratory in Germany have shown that when the total phosphorus concentration in the water body is 0.1mg/L, a UV device with a flow rate of 300L/h can reduce the photosynthetic efficiency of algae by 55% (as demonstrated by the reduction of the fluorescence parameter Fv/Fm from 0.62 to 0.28), significantly inhibiting the potential for explosion. The annual operating cost of the equipment is approximately 100 yuan (electricity bill + lamp tube replacement), which saves 60% compared to the algaecide solution, and there is no risk of chemical residue.
In practical applications, it is necessary to match the water body parameters: 3 watts of UV power is required for every 100 liters of capacity, and the flow rate should be controlled at 1.5 times the total circulation volume of the fish tank (for example, a 200-liter tank should match 500L/h). The 2022 North American Aquarium Enthusiasts Survey Report indicates that 85% of users have reduced the frequency of algae removal (from twice a week to once every two weeks) after using UV equipment, and the lifespan of the lamps has been extended by 40% (due to weakened competition for light). However, it should be noted that the efficiency of UV for attached algae (such as black-hair algae) is only 35%, and it needs to be combined with the regulation of CO₂ concentration (maintained at 20-30 PPM) to achieve synergistic control. The UV system certified by the EU CE can be safely applied to coral tanks, and the measured deviation of calcium ion concentration is ≤1.2%.
The comprehensive benefit assessment shows that under the condition of a light intensity of 2000lux, continuous operation of the UV Filter can extend the algae regeneration cycle from 48 hours to 120 hours. The operation and maintenance data of the Shedd Aquarium in Chicago confirm that this system reduces the cost of cleaning labor by 35% (saving 50 working hours annually), while increasing the survival rate of ornamental fish (with a growth rate ranging from 82% to 96%). For highly eutrophic water bodies (nitrate >20mg/L), the combined denitrification filtration can reduce the recurrence rate of algae to 8%, achieving ecosystem-level control.