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View Full Version : Trickle filter removes nitrates!!!



endless
Tue Feb 20, 2007, 07:19 AM
I dont know how true the above statement is but according to some koi enthusiasts, they have documented that trickle filters remove nitrates. I know it sounds contradictory but have a read of the link below. In particular look at the post on page 8 and 10 by a guy called "DocRodConrad" as he gives an explanation as to how trickle filters remove nitrate.

http://www.koi.com.my/forum/KOI_Talk_C1/Pond_Construction_%26_Water_Filtering_System_F4/High_Nitrates_Level_Try_This%21_P3071

What are your guys thoughts on this. Do you think that it really works or just a fairytale too good to be true?

elvip
Tue Feb 20, 2007, 10:48 PM
Hi Endless,
I use a trickle system on one of my large (6ft) display tanks along with an Eheim canister filter.
I must say that I have never really noticed the nitrate levels going up in this tank, but I religiously change 1/3 of the water on a weekly basis so as to maintain the status quo and healthy water readings.
One thing I have noticed is that a lot of 'gunk' (not sure what is is) - collects at the bottom of the trickle system and I clean this out weekly also - because I believe that if left in the trickle filter, it might actually put nitrates back into the system - not completely sure about this though. Therefore I find these sort of filters higher maintainance than canister filters etc; however the water in the tank is generally crystal clear.
I wonder if I reduced the number of water changes on this sytem, whether the nitrates would not creep up?? - would be interesting to see, but not sure if I would be willing to risk the potential consequences of not changing my water on a weekly basis :wink:
Cheers
Elvip

endless
Tue Feb 20, 2007, 11:53 PM
Hi elvip, i believe you are right in thinking that removing the gunk reduces nitrates. Afterall if the gunk/organic waste is not removed it will eventually be converted to ammonia then to nitrite and finally nitrate. I have an 8x2x2 tank with about 20 adult discus and i cant seem to reduce the nitrate to an acceptable level. I think my filters are working too efficiently (im running an eheim pro3, fluval fx5, eheim pro 2 and jebo 838) and converting organic waste to nitrates too fast. I change 30% of the water every second day (the water of course goes to the garden) but still cannot get the nitrates below 40ppm. I might get it down to 10ppm through a huge water change but it shots straight back up the next day. I also clean my filters every 1-2 months. In saying that all my discus are healthy and big and the high nitrates dont seem to bother them or dont seem to have affected their growth rate.

elvip
Wed Feb 21, 2007, 12:50 AM
Hi again Endless,
I assume you're not over feeding etc - factors that contribute to increased nitrates??
It might be worth your while to try a trickle system - but these aren't cheap, and it would be a chance you take in seeing whether it does the trick or not for you.
I personally think if the fish are OK and not suffering from these higher nitrate levels - then there is no need to worry too much about it. At the end of the day it is the health & happiness of the fish that we are ultimately concerned with.
What are your thoughts!
Elvip

endless
Wed Feb 21, 2007, 01:32 AM
Hi elvip,

I totally agree with you. On your question about overfeeding, i do feed my fish quite heavily but mainly on dry food which they always consume within 5 minutes. As a supplement on the dry food i also feed beefheart mix and frozen brine shrimp. Although my fish are doing great it would be nice to get the nitrates down since everyone on this forum generally regards high nitrates as a bad thing. I was thinking of building a cheap overflow box and using plastic storage containers stacked on top of each other from bunnings filled with cheap bioballs to test the theory out. The only problem is finding cheap bioballs. If i ever do get around doing this i will certainly post the results up.

samir
Wed Feb 21, 2007, 04:44 AM
imo this is the tree you need to be barking up :P

http://www.aquariumsuppliesaustralia.com.au/store/cart.php?m=product_detail&p=257

endless
Wed Feb 21, 2007, 06:09 AM
Hey samir, if i get that unit i still need to buy a pump that does 1-3l/hr. That kind of pump costs heaps doesnt it?

the german
Wed Feb 21, 2007, 07:24 AM
you could conect this unit on a bypass to your filter.

the german
Wed Feb 21, 2007, 07:28 AM
and then with a valve you can reduce the flow so much down hat you get
the amount on water you like to go thru.
i used one of this denitrifiers back in germany,it was a little black box on a bypass and you had to feed the bacteria a spezial solution every third day,it worked a treat.
it made 20l/h.

fishgeek
Wed Feb 21, 2007, 08:06 AM
the suggestion that the trickle filter denitrate, makes me assume there must be some anaerobic area's within it

readings of ntrate on colorimetric tests can be miisleading and should be a guide rather than taken as an absolute
as with you if the fish are good i tend to not worry

my trickle filter has just the overflow's from a bank of tanks into a hanging basket full of filter wool
beneath the hanging basket is that plastic grid that is used in nursery situations(basically 1 cm square nylon grid mesh stuff) i have rolled it in several loose wraps and attached beneath the hanging basket for water to run down
intially i called it a moss tower and had moss growing trough it .. this grw too well and blocked the light to itself so it broke away after time

no i have ricca (which tends to not get thick) growing all down it , plus the occasional java fern .. i guess those would reduce my nitrate

andrew

lesley
Sat Feb 24, 2007, 03:47 AM
Hi Andrew,

sounds interesting, any pics?

endless
Sun Feb 25, 2007, 12:30 AM
This is the explanation given as to how trickle filters remove nitrates


When denitrification is studied in scientific detail, the only way the nitrogen leaves the water, other than by plant absorption, is to convert nitrite to nitrous oxide and nitric oxide. This is true whether the denitrification occurs with either aerobic or anerobic bacteria. So how trickle towers work to denitrify (remove nitrogen) is independent of whether we argue it is done with aerobic or anerobic bacteria. If the nitrogen is already nitrate, the bacteria must first convert it to nitrite before making it into nitrous oxide and nitric oxide. If the pond starts up on trickle tower filtration, nitrates should never form if the trickle towers are properly constucted with enough capacity.

There is another trick to starting up new ponds, namely the use of a large dose of calcium bentonite clay. The clay chemically binds the nitrite until the TT biofilms convert it to nitric oxide and nitrous oxide. So with the right formula of clay charge and TT construction, a new pond and new filter never has to have any measurable nitrites, or nitrates. I have done that myself literally dozens of times in "virgin new trickle tower" cycling experiments combined with high doses of bentonite clay.

The problem getting rid of nitrates in submerged media filtration is that the nitrous oxide and nitric oxide products of denitrification biofilm reactions redissolve in the water, and form more nitrites and nitrates. So these products of denitrification have a hard time to leave the water, and go around and around in a big circle.

In trickle tower filtration, those gases just exit to the air as they leave the trickle tower biofilm. And the nitrogen is gone. As has been discussed on this forum for several years now, it works.

On the matter of ORP readings, trickle towers increase ORP readings significantly. That is why trickle tower filters cure both green water algae and stringy algae, the ORP levels are increased by about 100 units to literally "burn up" the algae colonies in oxidation reactions. I have studied this effect for several years.

It continues to be a pleasure to have this valuable discussion thread saved for the ponding community as an excellent reference.
Roddy Conrad, Charleston, WV, USA

Does this makes sense?

fishgeek
Sun Mar 11, 2007, 12:44 PM
lesley, apologies for the delay

is just a hanging basket full of filter wool and then the nnylon gridwith riccia growing through