Are vegetable filters effective??

DonB · Post by **DonB** » Sat Apr 01, 2006 6:11 pm

I went to the Sparsholt Training Colledge open day last weekend. A very good day out too.

One of their fish experts when talking about nitrates and their experiments and vast knowledge obtained said that by calculation vegetable filters unless enormous in size (over 100 times the area of the pond for the average koi pond) were of little effect.

They had calculated the amount of nitrates required to produce the vegetation and quoted the average leaf size, density in the filter etc. and although the root growth was excluded the conclusion was that they were a waste of time as so little nitrate could be removed. The water had to be in the filter for hours as well for the exchange to be made.

Has anyone any informed comments on this as I don't usually believe everything I hear even when backed up with facts.

Don

chita · Post by **chita** » Sat Apr 01, 2006 9:05 pm

I'd say that about sums up my first and only experience around 29 years ago, and it held enough crap to feed several pigs. Another of those age old myths propagated by those who never tried it, or because they had done it wanted to believe it worked.

Chi

macaws fly · Post by **macaws fly** » Sat Apr 01, 2006 9:11 pm

i agree. the only good vegetable is a lettuce thrown into the pond as a treat..

Post by **B.Scott** » Sat Apr 01, 2006 10:04 pm

Yep I'd say you all have that one nailed

Werner · Post by **Werner** » Fri Apr 21, 2006 10:28 pm

Don-- Like a lot of things in this hobby, too little information can lead you down the wrong path.

I'll try to make this as clear and short as possible:

Veggie filter DO work to keep the pond water clear, outcompeting Algae for nutrients not limited to nitrates.

Veggie filters add beauty to a pond. If built correctly, even large Koi will not be able to destroy them.

Veggie filters require maintenance, different kind of maintenance, i.e. root pruning and sediment flushing, just like any other filter. The crap doesn't dissapear into thin air like some other filters claim.

Veggie filters WILL NOT work when plants are dormant during cold months and are therefore best suited to tropical and sub-tropical climates if you want year round Veggie filtration.

Veggie filters absorb nutrients through the roots, so I'm not sure how anyone could conduct a test any test, without taking root absorption into account.

Veggie filters have their place, but are not for everyone and are not the "Holy Grail" of maintenance free filters.

chita · Post by **chita** » Sun Apr 23, 2006 9:10 am

A fair and detailed analysis I'd say

Chi

fatherted · Post by **fatherted** » Sun Apr 23, 2006 9:58 am

Suggestions for effective alternative nitrate removal?

Post by **B.Scott** » Sun Apr 23, 2006 1:00 pm

Water changes!

B.Scott

chita · Post by **chita** » Sun Apr 23, 2006 7:21 pm

With optimum filtration Nitrates can be accomodated in a similar way Nitrites are, via bio conversion. Unfortunately it does require a more complex filter system, preceded by some study on the subject, I've done it myself but it wasn't easy.

Chi

fatherted · Post by **fatherted** » Sun Apr 23, 2006 10:22 pm

Well, one step at a time. I will have to revisit this with you all at a later date. Must get the current equipment up and working in the new pond before I go on to this.

Tap water has a pretty high nitrate level round here Scottie!