Fluid bed filters

[fkn001]

Hallo all

Does anyone have an opinion on fluid bed sand filters ? I recently got a Cloverleaf fluid bed filter for my 1300 liter growing-on tank, the MP25 that is supposedly able to handle 650 g of fish food per day. the allure was the huge surface area and that it is more or less self-cleaning, needed only the occasional top-up with sand as it wears away.

A friend bought the larger MP70, also installed on a growing-on tank, and so far we are pretty impressed with the function of the filter/bio-reactor or whatever we prefer to call it.

It seems to do the job perfectly, however we are nowhere near to pushing the filters to the limit, feeding is app. 1/5 of what their "rating" is.

This type of filter is almost unknown here in Denmark, except among the marine aquarium folks and commercial fish farmers. It seems too good to be true, I mean, why bother with any other bio media, if a few kilos of cheap sand can do the job, allowing for the number of filters required to get enough flow for an overall turnover of pond volume in 1-2 hours. Just the foot print compared to say a Nexus or Bead filter is enough to focus my attention, not to mention the price.

I have seem Fluid bed sand filters, laaaarge ones, on many salmon farms in Norway and Chile, and the technical people at the farms are very pleased with them.

Cheers

Flemming

[GERRY5]

hi flemming, fluid bed filters are pretty good at giving you good water quality and good bio reasonably quickly and do provide a massive surface area for the bio to grow on , but i would not run a koi pond solely on a fluid bed system alone, as a supplimentary system yes, along side a nexus =koi heaven ....you cant overfilter a pond and a fluid bed will certainly help with water quality...gerry.......ps welcome to koi quest

[fkn001]

Hi Gerry, well, a Nexus is a fluid bed filter, and why not use a fluid bed sand filter exclusively for the bio filtration, but only use it as an addition ?

I am not proposing doing away with mechanical filtration. I have a rotor sieve in a settling tank as my first filter chamber, and from there it enters various bio chambers, brushes, bio balls, a fluid bed section with K1 and Bio chips, then to 2 tornado protein skimmers with ozone injection controlled by a redox meter and finally through UV back to pond. why not replace the bio part with 3-4 fluid sand filters and do away with the existing bio set-up = less maintenance and much less space.

Regarding the rotor sieve, I have never seen one on any UK site or seen it discussed on forums. they are quite popular here, I have had mine for 1,5 years now, and I swear by it. It has been running non-stop with never a hiccup, and only needs cleaning every 6-8 weeks in summer, less during the colder period and it takes 5 minutes or so. it has a 200 micron screen, is powered by a 60 W Seerose pump and I have added a perforated air hose around the bottom. Beats me why rotor sieves seems to be unknown in the UK. I would not dream of building a pond without this being the first item on my filtration list and everyone I know who has one is of the same opinion. have attached a picture

Rotor Sieve in settling tank with bottom drain

Rotor Sieve__skaleret.jpg (116.26 KiB) Viewed 9868 times

It is quite interesting to see the difference in equipment/gadgets used in various countries, i.e. in Germany vs the UK vs the US vs Denmark etc. this of course has meant ordering stuff from all over, even a demand feeder from the US which is very nice. I now have several items that nobody else to my knowledge has here and is a good topic for discussion when other koi guys drop by....

/Flemming

[GERRY5]

hi flemming ,my understanding of a roto sieve is that it is very smilar in the way it works to a nexus answer, most people running that in the past here in the uk have ditched them in favour of the easy then the fluidised that you get witha 200\300 , cost of running (leccy)etc comes into play of course...as for the sand fluidised filter it tends to grow bio very quickly and does provide a massive surface area with the sand it holds ,as long as you dont blow the sand out the top and all over the pond floor i think theyre a good addition\supplimentry filtration...