nitrate level
 

Hw to reduce the level of nitrate in the water?

Frequent water change.

yep..
or u can put in some hornwat , those fast growing plant.. good nitrate asborber. but i think goldfish will make a mess out of it..
or u might want to try using the guan yin tek .. just tie on the tank leaving the roots submerge.

Most efffective is lower bio-load, next easiest is water change. You could experiement with building a denitrator too. ;)

Besides that, growth of wall algae can help to reduce nitrate if you are using a tub.

But frequent water change is always the best.

The nitrate problem is researched extensively by diana walstrad. You can find information on the very good book. (she only wrote one good book, made a lot of money i think)

The summary is this, plants do consume nitrate but they will need to convert nitrate to ammonium first. hence if you have ammonia in the water, they will consume ammonia first then do the conversion once ammonia is depleted.

A very neat device is discussed advently here in the forum.
It is called the denitrator. Nitrate levels as high as 100pm can be reduced or eliminated altogether. The advantages are many with good control. My experience to share here is, probably more relevant to the brothers who have tried it than starters, use a moderately high flow rate first. not the other way around. Then slowly reduce it overtime.

:p

2 suggestions.

1. keep up your WC schedule. Plants/denitrator probably introduced more problems that what you try to solve. My tank has gone from complicated setup to today's : airpump + OHF with WC every 3-4 days.


2. Try not to overload the biosystem. I once had 9 gfs in 3ft. All sorts of problem popping up trying to fix the ammonia/nitrate issue: Filter wool that requires changes every 2 days, white worms starting to appear, tank coated with slim/brown algae. Fish fell sick after 2-3 months and I am losing casualty. Now I have 4 gfs in a 3ft tank and bioload is manageable.