The BEST algae filter is a Whole House Filter, 5 micron size...

[OldTimer]

Hello again. I today made a post and 2 replies to my DIY project which has benefited my simple little 20g planted tank. I went to Lowes and bought a Whole House Filter precisely similar to the one I installed on my home plumbing system and I gotta say that this 20 dollar filter beats the pants off anything claiming a better means of aquarium filtration.
The filter unit is just a hard plastic shell with an inlet and outlet precisely similar to and RO system. The WHF kind takes a 10x2 inch carbon / sediment filter insert and is rated at 5 microns and up. I use the 5 micron size and doing a look up, free planktonic algae is larger than 5 microns for many types... see this report...
https://msnucleus.org/watersheds/biological/microalgaegen.html
Anyway, this type of filter can be linked in series as an RO/DI system is so that the one after the 5 micron filter unit can be filled with biofilter media.
All I can say is... for a total cost of 50 dollars for the one unit I'm running at present and fittings and hose minus an aquarium pump solves free swimming aquarium diseases plus green water and also milky water. No one contraption on the market today can do this while all promise it can. Filter media for a WHF is 13-14 dollars for 2 cartridges and the one in my house lasts 3 months and longer... try and boast of *that* with a
sump filter sock !

 

[NickAu]

What filter? Can you give more detail, if its what I think it is then its not suitable for fish as it may remove too much good stuff as well.

 

[DrRob]

I think he's talking about the cartridge filters that you get on RO units. Great for purpose, but, as you say, they can be too aggressive. As water polishers they're probably fine, but I can't see them replacing a normal filter for sheer biological grunt, but paired with the right piece of kit as an add on, for infrequent use, I can see an advantage, although I'd probably not bother with the carbon cartridge, just 10 and 5 micron cartridges, and maybe a chemical reactor if I wanted one for something else.