Nitrate filter

[Wills]

I first heard of home made nitrate filters about a year ago using sand beds and various DIY systems and as much as I hate nitrate I've never gone down the home made route with my tanks. And I've always wondered why none of the manufacturers seemed to make a kit for this as there is a massive market for it IMO - a lot of tap water in the UK contains levels of nitrate less than ideal for health or fish keeping and the popularity of keeping big messy fish always goes up and down.

Anyway, perusing items tonight I came across this bit of kit

https://marineaquatics.co.uk/shop/reactors/deltec-reactors/deltec-nitrate-filters/

Wondered what people thought of them and if its something its worth investing in for the right kind of set up?

Wills

 

[Byron]

I'm linking our member @AbbeysDad as he has battled high source water nitrate successfully and he will have advice on this.

 

[AmyKieran]

I first heard of home made nitrate filters about a year ago using sand beds and various DIY systems and as much as I hate nitrate I've never gone down the home made route with my tanks. And I've always wondered why none of the manufacturers seemed to make a kit for this as there is a massive market for it IMO - a lot of tap water in the UK contains levels of nitrate less than ideal for health or fish keeping and the popularity of keeping big messy fish always goes up and down.

Anyway, perusing items tonight I came across this bit of kit

https://marineaquatics.co.uk/shop/reactors/deltec-reactors/deltec-nitrate-filters/

Wondered what people thought of them and if its something its worth investing in for the right kind of set up?

Wills

Slightly off topic kind of but I thought ide ask, have you ever tried products such as tetras nitrate minus? I see them on the shelf and wonder if it could actually do just that or if it’s just another snake oil product

 

[Colin_T]

I first heard of home made nitrate filters about a year ago using sand beds and various DIY systems and as much as I hate nitrate I've never gone down the home made route with my tanks. And I've always wondered why none of the manufacturers seemed to make a kit for this as there is a massive market for it IMO - a lot of tap water in the UK contains levels of nitrate less than ideal for health or fish keeping and the popularity of keeping big messy fish always goes up and down.

Anyway, perusing items tonight I came across this bit of kit

https://marineaquatics.co.uk/shop/reactors/deltec-reactors/deltec-nitrate-filters/

Wondered what people thought of them and if its something its worth investing in for the right kind of set up?

Wills

Sera brought out their first de-nitrater in the 80s. It was a long narrow filter that hung on the back of the tank and had a very slow flow rate of water going through it (1 drop every couple of seconds). The unit was fed carbon tablets that cost about $1.00 each ($30.00 for 30 tablets). The de-nitrating filter took around 6 weeks to develop the anaerobic bacteria and when functioning, it would keep nitrates at 0ppm.

After 6 months of running mine I reduced the carbon tablets and eventually stopped using them altogether. The filter kept running and the nitrates remained on 0ppm.

I used mine on a marine tank.

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If you have a freshwater tank, grow lots of floating plants and nitrates will be less of an issue.

In a Rift Lake cichlid tank, grow floating plants and have some big pieces (6+ inches diameter) of limestone or sandstone in the aquarium. Anaerobic bacteria grow inside the large pieces of rock and help to get rid of nitrates.

In a marine tank, grow marine algae like Caulerpa and Halimeda, and have big pieces of limestone and sandstone in the tank.

 

[Colin_T]

Slightly off topic kind of but I thought ide ask, have you ever tried products such as tetras nitrate minus? I see them on the shelf and wonder if it could actually do just that or if it’s just another snake oil product

snake oil

There are some products that consist of bacteria that break down nitrates, but most of the bacteria that do that are anaerobic and can't live in an aquarium because there is too much oxygen.

If you want to try some of these items, you can, but you will probably be wasting your money.

The best way to remove nitrates is with live plants and water changes.

 

[Wills]

I'm linking our member @AbbeysDad as he has battled high source water nitrate successfully and he will have advice on this.

Thanks Byron, AbbeysDad has really helped me on my current tank which I use an on demand RO unit for now but I have dreams of a bigger tank that my direct flow unit wont work for and I don't have space to store RO water for a tank that size so I was thinking if I could use a product like Prime to de-toxify the nitrate in my tap water and let a product like this keep on top of the overall level.

Wills

 

[Wills]

Sera brought out their first de-nitrater in the 80s. It was a long narrow filter that hung on the back of the tank and had a very slow flow rate of water going through it (1 drop every couple of seconds). The unit was fed carbon tablets that cost about $1.00 each ($30.00 for 30 tablets). The de-nitrating filter took around 6 weeks to develop the anaerobic bacteria and when functioning, it would keep nitrates at 0ppm.

After 6 months of running mine I reduced the carbon tablets and eventually stopped using them altogether. The filter kept running and the nitrates remained on 0ppm.

I used mine on a marine tank.

--------------
If you have a freshwater tank, grow lots of floating plants and nitrates will be less of an issue.

In a Rift Lake cichlid tank, grow floating plants and have some big pieces (6+ inches diameter) of limestone or sandstone in the aquarium. Anaerobic bacteria grow inside the large pieces of rock and help to get rid of nitrates.

In a marine tank, grow marine algae like Caulerpa and Halimeda, and have big pieces of limestone and sandstone in the tank.

Thanks Colin thats really interesting! The plan is for a central american tank so some kind of pourous rock might be ok? I've found this one which I think is the same thing? Nitrate Reactor

Is it more commonly called a Nitrate Reactor on the marine side of the hobby? Would make sense as to why I've not found them if I've been searching for filters haha.

 

[TwoTankAmin]

The bacteria that do denitrification in aquariums are called facultative anaerobes. They have the ability to function in both aerobic or anaerobic environments. If there is oxygen in the water then use that. But when the oxygen in the water is depleted and there is nitrate, they switch to using that.

There are actually denitrifying bacteria within the same biofilm where the nitrifiers live. The problem is they are only there in limited numbers which are insufficient to process all the nitrate created.

There is a great study done years back about what goes on in the substrate when there are plants or not plants. nasically tooted live plants sent there roots into anaerobic areas of the substrate, It was discovered that many plants will transport oxygen down to their roots and then release it into the anaerobic areas. This turns them aerobic and that foster colonization of the nitrifiers. In an unplanted substrate there is too little oxygen to support nitrification once the depth gets much over about 1/2 inch (1.27 cm).

But the most interesting discover from the research is once the plant has fostered an aerobic zone around the roots, denitrifying zones develop above and below it. They process the nitrate.

This gets even more interesting to those fish keepers who use massive amounts of high quality foam thet is pore size controlled and which is far superioir to the cheaper sponges and foams available. I have been switch to this over the past 7 years. I am usubg Hamburg Mattenfilters and large foam cubes. I have the needed denitrifying bacteria colonizing these. I know because I finally stop using a nitrate test kit. I have not owned on for some time.

Here is why massive foam media works to foster denitrification. Because of the massive number of pores per inch, they are an uncountable number of places bacteria can colonize and even more routes water can taje to move through the media. As the various bacteria coonize, and there are way more kinds of them in the biofilm in which they live than most fish keepers know. Some of thes are the facultative anaerobes. These take some time to colonize and they start out using the oxygen in the water that reaches them. But over time more and more bacteria are colonizing and what happens is some pathways through the foam become anaerobic because the bacteria along the way use it up. But they are also producing nitrate. And when this starts to move through certain areas of the foam, the facultative bacteria switch to using the nitrate the other bacteria have created while using up the oxygen.

It is important to understand that the flow rates for the water following various routs through the foam changes as more biofilms builtds up. The facultative bacteria need a slower flow to work on the nitrate. Moreover the nature of what lives where on various pathways yjtough the foam may also change. However, if an anaerobic area suddenly becomes aerobic again, the facultative bacteria simply go back to using oxygen and the nitrate is not used.

However, over time there will be both sufficient facultative anaerobes built up in various parts of the foam such that nitrate and not oxygen will be reaching some of them. And that is why tanks with such large foam filters ultimately do denitrification which means there will be a lot less nitrate in the water.

There is a second benefit to using massive amounts of the right foam. It takes a lot longer to clog than almost any other media. I had a canister filter loaded 100% with such foam and it took about 3.5 year, maybe a bit more, before I needed to clean it the first time. Most of my Mattenfilters have been running for years not needing to be removed and rinsed. (I do run a siphon across the front side of the foam for about 30 seconds when I do weekly water changes.) The foam cubes get rinsed about every 3 weeks as opposed to weekly when I used more "traditional" sponge filters. These did not help with nitrate much at all.

Also, if one has serious nitrate issues it may be difficult to wait for the facultatiive bacteria to colonize in numbers sufficient to help. In such cased a dedicated denitrifying system may be needed. But as noted these need very slow flow,

Chemicals are not the way to deal with this stuff. Nobody would suggest not having a filter with bacteria but instead regular adding chemicals to a tank to remove ammonia. This is neither economical nor efficient. The same applies to nitrate removal. For many of us, weekly water changes are sufficient for controlling nitrate. For many of us live plants use the ammonia and thus do not create nitrate. They may also use available nitrate when not enough ammonia is available.

Once last observation about massive foam filtration. The lifeforms inside the foam also comsume organic waste. U use these filters in my pleco breeding tanks which have some of the clearest water in any of my tanks despite heavy stocking of professional poopers.

 

[Colin_T]

Once last observation about massive foam filtration. The lifeforms inside the foam also comsume organic waste. U use these filters in my pleco breeding tanks which have some of the clearest water in any of my tanks despite heavy stocking of professional poopers.

LOL professional poopers


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Thanks Colin that's really interesting! The plan is for a central American tank so some kind of porous rock might be ok? I've found this one which I think is the same thing? Nitrate Reactor

Is it more commonly called a Nitrate Reactor on the marine side of the hobby? Would make sense as to why I've not found them if I've been searching for filters haha.

Yes most places call them nitrate reactors or denitraters. You can also buy nitrate removing resins that are like carbon but remove nitrates.

I'm not sure if the denitrating resins or nitrate reactors work in freshwater. I assume they do but only know them from marine tanks.

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Back in the 90s people started using refugiums on marine tanks. They are basically a sump with rock and macro algae in. The tank water flows through the refugium and the macro algae use ammonia and help keep nitrates lower.

Around 2005 people in Perth WA, started using deep sand beds and big pieces of rock for filtering marine tanks. They had 5-6 inches of fine sand on the bottom of the tank and it was aerobic in the top inch but anaerobic in the bottom half. The big pieces of rock had aerobic bacteria on the outside and anaerobic bacteria on the inside.

The bacteria on the outside dealt with ammonia and nitrite, while the anaerobic bacteria inside the rock got rid of nitrates. These tanks had no filters but did use water pumps to circulate water around the aquarium. The tanks contained mainly corals and a few fish, but did not contain any macro algae and there were no sumps connected to them. The filtration was actually done by the bacteria on and in the rocks.

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For a freshwater cichlid tank you won't be able to use a deep sand bed because it will be dug up by the fish. Having some big rocks might help. But the easiest way to go would be a sump full of plants. The tank water would flow into a sump, ammonia would be removed by the plants, and a sponge on the return pump would help to remove any remaining ammonia or nitrite from the water. The sponge on the return pump would act as a mechanical and biological filter. You could also have some white filter matt at the start of the sump to catch course particles from the main tank.

Add some floating and normal aquatic plants to the main display tank (in addition to the ones in the sump), and you should be able to keep nitrates pretty low between water changes.

You could also keep shrimp in the sump and feed the excess shrimp to the fish.

 

[Byron]

Thanks Byron, AbbeysDad has really helped me on my current tank which I use an on demand RO unit for now but I have dreams of a bigger tank that my direct flow unit wont work for and I don't have space to store RO water for a tank that size so I was thinking if I could use a product like Prime to de-toxify the nitrate in my tap water and let a product like this keep on top of the overall level.

Wills

I do not recommend Prime. It is not a "treatment" (which is what you need). It is a water conditioner, and the detoxifying of nitrate is temporary, Seachem says 24-36 hours, after which any nitrate is back to the toxic form. They do not tell you how this product does this, in fact in an email to me they admitted they did not know...which bothers me when I am using such a product in a tank of fish. But one thing is known, the TDS do multiply the more Prime you use, and this is also harmful to many fish.

Filtration aimed at the problem is your safest option.

 

[Wills]

I do not recommend Prime. It is not a "treatment" (which is what you need). It is a water conditioner, and the detoxifying of nitrate is temporary, Seachem says 24-36 hours, after which any nitrate is back to the toxic form. They do not tell you how this product does this, in fact in an email to me they admitted they did not know...which bothers me when I am using such a product in a tank of fish. But one thing is known, the TDS do multiply the more Prime you use, and this is also harmful to many fish.

Filtration aimed at the problem is your safest option.

Ah thats interesting I didn't realise it was a problematic product.

I agree definitely need the filtration option - the plan with the prime was to add it to tap water (with 20-30ppm Nitrate) let it detoxify it then before the toxicity of the nitrate became an issue the filter would have processed it (from memory to Oxygen?) Otherwise every time I do a water change I would be adding nitrate to the tank and I'm not totally sure how long it would take for a nitrate reactor/filter to process it through?

 

[Byron]

Ah thats interesting I didn't realise it was a problematic product.

I agree definitely need the filtration option - the plan with the prime was to add it to tap water (with 20-30ppm Nitrate) let it detoxify it then before the toxicity of the nitrate became an issue the filter would have processed it (from memory to Oxygen?) Otherwise every time I do a water change I would be adding nitrate to the tank and I'm not totally sure how long it would take for a nitrate reactor/filter to process it through?

This is where @AbbeysDad can help, he dealt with very high source water nitrate long-term.

Prime's "detoxifying" of ammonia, nitrite or nitrate is in all cases temporary and intended to solve the immediate problem of having one or more of these in the source water. The aim is that by the end of the 24-36 hours, the various bacteria (or plants) will easily have control and the toxic ammonia/nitrite/nitrate will no longer be an issue. High levels of nitrate probably pose additional problems, so again, a more permanent solution is best. Rather than dumping in chemicals that continue to build up harming fish.

 

[AbbeysDad]

This is where @AbbeysDad can help, he dealt with very high source water nitrate long-term.

Please see My Nitrate Fight. API Nitra-Zorb is a resin that will extract nitrate from water and can be recharged and reused many times with ordinary salt water. The downside to using Nitra-Zorb pouches in a filter is that in time, the resin will get coated with detritus and become ineffective. I got past this by repurposing an API Tap Water filter which I emptied, filled with API Nitra-Zorb and filtered clean fresh water to use for water changes. My article mentions all of this. (A similar filter could be easily made with PVC pipe).
Footnote: I tried UNSUCCESSFULLY for the longest time to culture anoxic/anaerobic bacteria to convert nitrates into harmless nitrogen gas. I'm not saying that it can't be done, but with my many attempts I never saw a noticeable reduction in tank nitrates. Speaking of which, also check out Lowering Aquarium Nitrates (basic stuff but worth the read).

 

[oafish]

I used the Pozzani nitrate filter as an "off the shelf" solution. It worked well, reducing my Hull tap water from 40ppm nitrate down to 0ppm but I found the filters didn't last long, maybe around 200-300 litres before the nitrates started going back up, so it was fairly expensive for water changes on my 240 litre tank.

I have gone full RODI now but, after seeing AbbeysDad comments above, I might try filling one of the old Pozzani cartridges with the nitra zorb to see how effective it is for water changes.

 

[Wills]

I used the Pozzani nitrate filter as an "off the shelf" solution. It worked well, reducing my Hull tap water from 40ppm nitrate down to 0ppm but I found the filters didn't last long, maybe around 200-300 litres before the nitrates started going back up, so it was fairly expensive for water changes on my 240 litre tank.

I have gone full RODI now but, after seeing AbbeysDad comments above, I might try filling one of the old Pozzani cartridges with the nitra zorb to see how effective it is for water changes.

Ah Hull you utter hole... (no one else is aloud to say that). Its really nice having someone else here to understand the struggles! Have you ever looked at Riparium planting? With some plants like Monsterra or Peace Lillys (there are loads more too).

Wills