Hi Can anyone advise me the best external filter for a 145 litre tank? I am guessing it will be an ehime of some sort. Is there some kind of light in some filters that kills any algae that passes through?
Actually, hang on filter(HOB) is good enough if your tank length is 3 feet or less.
For hang on filter, you can consider two Seachem Tidal 35 or one Seachem Tidal 55.
Usually I prefer two filters for backup purpose and I can clean each one on separate weeks to prevent losing too much beneficial bacteria at one time.
If you prefer external Canister filter, you can consider Eheim Classic 250 (if you have fish that prefer slower flow of water) or Eheim Classic 350(if you have fish that prefer faster flow of water).
Eheim Classic are cheaper than other Eheim models.
But if you prefer a better quality filter from Eheim, you can consider Eheim Experience 150.
It depends on your budget.
As the world’s best-selling performance canister filter, the 7th generation 07 series features Fluval’s eTEC (Efficient Technology) state-of-the-art materials and design refinements which make them ultra-quiet, powerful, energy efficient and user friendly for aquariums 10 to 100 US Gal. (40-500 L).
For easy cleaning/maintenence, you can also consider Oase external filter.
Description Integrated heater – Provides precise and uniform temperature levels and reduces the amount of equipment seen inside the aquarium by housing the heater in the unit Compact filter with large filter surface – Multi-staged mechanical, biological, and chemical filtration provides clear...
But the filter case material/design seemed to be average only.
UV light can kill algae spores in the water especially if you encounter green water algae.
But the UV light may not be able to have any effect on algae that grows on the plants, rocks, woods, etc.
So, if the algae comes from the plants, rocks, etc, you can't kill the algae provided you sterilized all the plants and rocks with Hydrogen peroxide or bleach or other chemical.
I think what the shop means is that a lot (not all) Tropica plants are grown in vitro so they do not have any snails or chemicals that could kill shrimps on them. In vitro plants are grown in sterile conditions.