block built filter

stuboy00 · Post by **stuboy00** » Sun Jul 15, 2007 8:55 am

hi everybody,
looking for some advice and help i have decided after long hard discussion with er in doors to build a block filter under what will be our new decking size wise for the filter will be 4m longx 3m wide x 1m deep i will have a settlement chamber of 4m longx 1m widex 1m deep it will then go into 4 other chambers of 2m longx 1mx 1m the first will hold static k1 then into fluid k1 then into jap matting then the final chamber will be a couple of pumps for the returns,
is this going to work as i am quite a novice to the hobby and dont have much experience any info you have and tips will be greatly appreciated,the pond will be roughly 8,000 gals once finished

thank you,
stuart

Gazza · Post by **Gazza** » Sun Jul 15, 2007 10:42 am

Hi Stuart,

There are many that do use block built filters and many that don't i think its what you want that counts.Me personally i would go for a couple of Nexus Easy units which should fit into the space.

stuboy00 · Post by **stuboy00** » Sun Jul 15, 2007 11:12 am

hi gazza,
will 2 eazy's be man enough for the job? the reason i was thinking about the block filter was because i thought it would be cheaper than forking out big money on a nexus?

thanks,
stuart

Bob Hart · Post by **Bob Hart** » Sun Jul 15, 2007 11:58 am

Stuart,

Have you worked out all of the costs for building this, rendering it, fibreglassing it? Fibreglass starts at Ã‚Â£18/metre, so can add up quite quickly.

The key to block built filters is to get the settlement right and therefore when designing it you'll need to know hios much water you will pull through. So what pumping rate?

stuboy00 · Post by **stuboy00** » Sun Jul 15, 2007 11:45 pm

hi bob,
i will be doing the works myself base, block and will be using aquakote instead of fibreglass as for circulating the water i was going to use my 2 5500 pumps which will turn over just short of half the pond volume every hour

thanks,
stuart

Bob Hart · Post by **Bob Hart** » Mon Jul 16, 2007 7:21 am

Stu,

I would say you are under pumping, but thats just my opinion. The old rule of once ever 2-hours is old hat really. Once an hour is a better rule these days.

The difficulty with block built is once it's built you are stuck with it, you cant easily make it begger/smaller. So you have to get the size and flow rates 100% coirrect from the start.

stuboy00 · Post by **stuboy00** » Mon Jul 16, 2007 8:32 am

hi bob,
what do you suggest i go with? 2 eazy's as gazza suggested? but will these be enough to filter the 8,000 gal pond? or should i try and get my hands on a secondhand 300 easy?

thanks,
stuart

Gazza · Post by **Gazza** » Mon Jul 16, 2007 7:31 pm

Hi Stuart,

I was thinking along the lines of two Neus 300 which would give you plenty of filtration and you could always add on something on a skimmer later

If you have a look through some posts by Bob you will see he has been upgrading his home made block built filters for years now.I for one can tell you how hard it is once they are built as i have been in the hole smashing the filters out

Capt Nemo · Post by **Capt Nemo** » Mon Jul 16, 2007 8:34 pm

stu,
I use 2 nexus 300's with eazys and a sieve on the skimmer.

so you'd be fine mate.

it will be alot of money to layout in one go, but I'm well happy with my water.

stuboy00 · Post by **stuboy00** » Mon Jul 16, 2007 9:03 pm

hey gazza,
i think thats what im going to do il try and get a hold of a 300 easy, dont suppose anybody knows of a secondhand one ? would the 300 and an eazy keep the water gin?

thanks,
stuart

Bob Hart · Post by **Bob Hart** » Mon Jul 16, 2007 9:47 pm

People do sell them Stu, just be quick when you see the advert. Check out ebay daily, some appear on there.

8000 gallons though, a Nexus 300 is sized at 7500 gallons. So you'll need more than one! I guess you'd be having 2 bottom drains, so perhaps a 300 on one drain and a 200 on the other, or 2 x 300's?

julian · Post by **julian** » Mon Jul 16, 2007 11:16 pm

Stuart - If you have the space and the ability to build a block built filter it would be a real shame not to go for it. The Nexus is a very efficient water treatment plant, but there should be more to a filter than just converting ammonia to nitrite to nitrate. It's about conditioning the water to provide a well balanced eco-system. Any combination of K1, Japanese matting or Bacteria House media could be used, PH buffers can be easily added and the more water you have without fish in it the better.
Block built or Bakki showers produce the best water quality. Only if space is at a premium should you settle for the Nexus.
Regards,
Julian

Gazza · Post by **Gazza** » Tue Jul 17, 2007 4:26 pm

Hi Julian,

How does a block built or bakki shower condition the water better than any other type of filtration as i don't have a block built filter nor a bakki shower

Unfortunately one of the major problems with block built is as you say needing the room and in my postage stamp garden i have no chance so had to couple some vortex units together,but they seem to do the job OK

stuboy00 · Post by **stuboy00** » Tue Jul 17, 2007 4:43 pm

hey gazza,julian

i have enough space as stated in my first post for a block filter of 12sq m i was planning to have raised decking built ontop of it to cover the filter i could stretch to 16sq m at a push? would this be ample?

thanks,
stuart

vippymini · Post by **vippymini** » Tue Jul 17, 2007 4:48 pm

stuart it all sounds good to have the space but the thought of making all that decking removable for maintanance gives me the shivers.... also the smell of the water coming up through the deck and the possibility of the decking preservative leeching/dripping into the water over such a large area is a worry....

get up to date and use the modern-day technology maybe one 300-easy and a gleaming bakki shower. dont hide the filter be proud of it.