Freshwater Nitrate Removal Products

Hi Folks,

I thought it would be useful to start a thread dealing exclusively with freshwater nitrate removal products. This could include both in-tank and external (e.g. tap water nitrate removal) products. These items may be filtration media, water additives and/or equipment. I'm not overlooking the importance of plants, which are undoubtedly helpful in controlling nitrate levels but not all tanks have plants in them.

In order to start the ball rolling, I was wondering if anyone has tried Tetra NitrateMinus. This is a simple liquid additive that works using a "completely biological process" (at least that's what it says on the bottle).

JPC

I looked at a bottle in a shop once and the only thing I remember is that it said that if you use it you only need to do water changes every 6 months  Looking at the back label on Tetra's website, they've removed that statement, it was a few years ago that I saw it.

The label also says

Regular usage of Tetra NitrateMinus helps ensure a low and stable nitrate level (less than 50 mg/l)

What exactly does this mean? We can keep nitrate at less than 50 mg/l (aka ppm) simply by doing water changes as that's the legal limit in tap water.
Does it actually do anything more than weekly water changes, not over stocking and not over feeding will do?
Saying that it "increases the activeness of microorganisms which feed on nitrate" doesn't tell us very much. How does it increase the activeness, does it contain live bacteria; something to boost the health of the bacteria?

I wish the website had more into.

Me again!

I've done quite a bit of digging about Tetra NitrateMinus. Somewhere on the web, there was a picture of the reverse side of the bottle of this stuff. Unfortunately, I can no longer find it and I didn't bookmark it. But, I think it said that this product contains something called polycaprolactone (PCL). Apparently, this is a biodegradable polymer (for which I read 'plastic'). It is used in aquaculture to - guess what - remove nitrate.

It appears that NitrateMinus is available as a liquid and also as 'Pearls'. My guess is that both these options contain PCL - one in a suspension of particles, the other as visible small spheres. That being the case, these particles/spheres would be slowly biodegraded by denitrifying bacteria. In order to do this, anaerobic conditions would be required if I've got my facts right. So, I started thinking how might this be achieved. Anaerobic bacteria grow in low/zero oxygen environments, which are characterized by minimal/zero water flow. My thoughts turned to sponge filters. So, when I've got other jobs out of the way (!), I'm going to pursue this idea further - unless someone reckons that my thinking is flawed.

JPC

I have tried this product after I had spike in nitrates due to removing a load of plants and it didn't work for me at all. I even tried adding it to the water before the water change and it still didn't work. The best remedy was to add nitrate eating plants.

This is the sponge filter in my betta's tank.
https://www.realaquatics.co.uk/aqua-one-filterair-30-sponge-filter.html

I don't think the sponge is thick enough to deplete oxygen enough to allow anaerobic bacteria to grow in the inner section. It doesn't look it in the photo but it is a good 3 inches across.