Hozelock Bioforce 2000UVC review
The first thing that anyone looks at with a filter is price. Pressurized filters are always more expensive than their gravity fed "conventional" cousins. And cleaning power can be better or worse for either. It comes down to application as to which is best for you. That's why I chose a pressurized filter for my pond, I wanted a filter able to continue to pump water upwards and that leaves pressurized.
Now With that out of the way, I chose the hozelock bioforce 2000UVC for a couple of initial non-experience related reasons.
First, at the various local pond/aquarium stores with koi, they use the bioforce filters overwhelmingly more than any other type.
Second, the size and capacity of the filter were perfect for my pond size, and the price where I got it was just right.
Despite that, nothing takes the place of actual experience in using a filter to decide if it's good. I've had this filter in use all last summer/fall and this spring and on. I'll break down the review to the various components of the filter and then an overall review of the unit in my pond.
UVC: The 13watt (seems weak but definitely isn't) UVC bulb is original to the filter and still working perfectly. The filter utilizes a center vertical UVC setup with a fin setup at the entrance that creates a swirl around the quartz glass the UV bulb is in. The UVC unit is the last thing the water passes by as it leaves the filter, which is important because many standalone units that aren't used in pressurized filter setups have it before the filter, letting the quartz glass get hit by all the debris and muck that the pump sends. By having it after, the UV bulb has remained completely clean for me after almost a year and I've never had to replace the quartz or worry about slime coating the quartz and thus rendering it useless for radiating the water. The swirling effect of the water allows a lower wattage bulb to be used to clean the same amount of water as many higher wattage standalone units, and by having the water pre-filtered, no debris blocks the UV rays from the organisms intended to be sterilized. The one downside of the UVC is the bulb, it's expensive as far as UV bulbs go and is extremely hard to find outside of the hozelock replacement parts.
Foam Pads: If there is anything I dont like about this filter, it's the foam pads. The pads are original to the unit, so they've been in use for almost a year. But they're beginning to lose their capacity for debris dramatically now, despite deep cleaning. The pads are also a holder of bacteria, so frequent cleaning is detrimental to the filter's performance despite having the renewed flowrate of a fully clean setup. The Bioforce 2000UVC has 3 thick foam pads, a very coarse pad, a medium coarse and then a fine pad. The order is pretty obvious, with the water entering from the pump at the top and swirling around downwards, the coarsest is on top, the finest on bottom. My experience with the pads is that there isn't enough coarse pad material after extended use, so muck will build up a water proof layer on the top of the coarse pad, causing the pressure to shrink it inward and water will just flow down the insides of the Bioforce unfiltered. My idea to fix this is to buy an even coarser foam and cut it to shape, then use the coarse foam that comes with the filter and finish off with the fine foam. I dont see much use in the middle foam as i've never had it capture anything that seemed larger than what the fine filter pad had caught. By having two very coarse pads, there is more capacity for larger debris, without having the top layer get caked, and less of a compression of the foam pads, which happens dramatically with the non-coarse pads.
Bio Media: The bioforce filter comes with small plastic media. This is adequate but can be improved greatly. I've added ceramic media and plan on removing the filter's original media completly and using ceramic and ribbon media exclusively in the "bio chamber". The biological media rests underneath the filter pads and is the middle of the water's path through the filter. It utilizes about the same volume as the filter pads do. Over the course of my use of this filter, I've never had a reading of ammonia, nitrite, or non-neutral PH levels.
Overall: I really am pleased with this filter, I'm not sure of how great it would be on a 2000 gallon pond, but on my 1200-1500 gallon pond it's definitiely doing the job. Unless you have a lot of dirt from outside of the pond, cleaning should be only carried out when the indicator is halfway up or more, which amounts to about once every 3-4 months and consists of hosing down the pads. I have 12 fish, if you have more, obviously you'll need to clean it more often. The filter can be buried if you want, and is made out of a durable black plastic for above ground locations. Replacement parts, if you need them, are available in various locations online and in some local shops (at least around me). The filter works great even when the output is higher than it. You'd be hard pressed to find a better pressurized filter, especially when you make the minor changes to bio-media and possibly replace the middle foam pad with the Coarse one and add an even coarser pad on top.