Mini Green Killing Machine Aquarium UV Filter Sterilizer with 3W UV Bulb Inside

I have two of these for two small tanks -- some reviewers talk about a GREEN LED function light , on both of mine the LED light showing that the UV bulb is working is in fact RED. The instructions say if the light is not working then the UV bulb needs replacing. So maybe the larger models have a different colour light . Using the uv 24/7 simple maths indicate that it will last for about 5 months. It does not seem to clean the glass but presumably it knocks out the algae spores in the water and after two weeks I think the green on the glass is not growing back so rapidly. The pump is very efficient but if you have messy fish like goldfish then you will have to rinse the sponge every few days but that's easily done. I replaced the plastic sponge with filter wool which traps finer particles as well. I bought this not for green cloudy water but to sterilise the water and eliminate any free-swimming Ich which was a problem in one tank. Using "Love Fish" formaldehyde/malachite green ich treatment in conjunction with this the problem went away within about 10 days .It is very quiet. UPDATE 4th jan 2021 -- I bought another from a different seller and this time the light for UV unit is GREEN, however, the original unit with RED light does a great job, no more algae... so the CONCLUSION IS that is does not matter what colour the light is, provided it is actually lit up -- that alone is the indication that the UV bulb is working. .

I had been messing around with algae killer & filtration for four weeks to clear a “bloom” with no effect ... Decided to buy the UV filter but I was sceptical of the claims for this filter & others ... I can honestly say to other sceptics - the filter did an excellent job & after two days the bloom was much improved ... After five days the water was crystal clear ... I now have the filter on 12 hours a day ... You have to change the UV part of the filter after around six months ... This is no more expensive than using/changing crystal clear filter cartridges every month

I had green water in my tank and was loosing the battle to clear the water. I saw this unit I have to say I was sceptical but I needed a solution. I set it up 3 days ago and it has started to clear the water very impressive.

I have a small 60l BiOrb that had a sudden algae bloom that I was unable to keep under control with a number of different chemical algae preventatives and partial water changes.This caused a virtually opaque green water and sludge build up in the filter. Though the shape of the product and location of the suction cups do not owe to a curved bowl I have managed to still fix it in place.The product arrived on Saturday and I write this on the following Tuesday with absolutely crystal clear water in my tank. I’m shocked it has worked so effectively, so quickly. Well worth the expense if you’re struggling to keep the green water at bay.

We kept on getting a reoccurring green bloom. First attempt was the usual partial water replacement and would be great for a couple days before tank turning green again. Did not want to go down chemical route due to possible risk to fish.We fitted this unit on Monday evening and by Wednesday there was a noticeable difference and by Saturday the tank was crystal clear. One thing to note is the pump output nozzle is closed when unboxed and you have turn in like opening a bottle top to open it. I suspect this may be cause of a couple of comments saying does not work.I would recommend powering down after a week to save on bulb life but leave in tank in case of return of green bloom. The only downside is both pump and UV lights have separate power leads so now have to have five power sockets next to tank but that is only minor compared to now having a fish tank that looks great again.

I purchased a total of 5 of these. One woke my daughter up at 4am buzzing loudly and terrifying the fish in her tank. Returned that. Another in my baby angel fish tank has just woken me up with that same loud buzzing noise at 3.30am! The fish are terrified. The third in my adult angel fish tank seems to be okay. The fourth in my community tank does not work. Algae is growing back less than a week from a tank overhaul and install of this UV. I have returned two to Amazon as faulty. There is another in the box, just arrived, which I have not put into my pea puffer tank as I was worried it would terrify them. Now I know that is being sent back unused after being woken up in the early hours of the morning, again. They are all cheap and faulty. I have ordered a total of 5 of these from Amazon and only 1 seems to be working. Serious waste of money. Should be withdrawn from sale.

Still in the tank after 4 months, so can't be all bad

Worked brilliantly, cleared an algae infested 90l tank in 4 days. I could not see the unit after it was placed into the tank, that’s how bad the algae bloom was in my tank. Within 4 hours started noticing a difference. 24 hours later a huge difference and by the 4th day the tank water was crystal clear! Looked like the fish were floating in air!! A brilliant piece of kit. I have not used it since as my tank water is still clear so hoping it will last a long time and if I need to use it again that it still works.