Nitrates! What worked in my large system!

[Roggio]

Backstory
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Let me start by saying I had a 600 gallon system with 100+ fish that ran well for years. I hardly attended to it because I was on the road for two, almost three years straight. Due to a large mangrove population and some rocks that had been cycled 15+ years my nutrients stayed low. The roots of the mangroves ended up breaking the PVC and compromising the structure.


I was forced to set up my new system with several large fish I couldn't part with. I dumped a ton of ammonia and bacteria additives to cycle this tank in as little time as possible. Bio-Spira had the best results. Fritz Turbo Start was added after the Bio and may have been too powerful. The cycle went to so a grinding halt until I added trace elements and phosphates. (Nitrates need some phosphates to process).
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What worked

I tried biopellets and always had issues with bacterial blooms. After a month of constant blooms I took them offline and chose to dose Vodka. I started a 5ml a day and over the course of a months ramped it up quickly to 15ml a day. I never saw any blooms but I had several short cycles that appeared as my rocks cycled. When this occurred I dosed Seachem Stability and Microbe-Lift Special blend. I also added a marinepure block in a low flow area, a gallon of marinepure spheres, and 4L of Seachem Matrix to aid the bacteria population. I have had a refugium this whole time but did not feel it could handle the nutrient load. Over the course of a month I only preformed one 40% water change (I was injured). The water change had little affect on nitrates.

Obviously everything I have done is anecdotal evidence but I feel the Matrix/bacteria/vodka blend was the strongest combatant to nitrates.

I will be running a Pond Matrix experiment on a tank that has been running for a few months with high nitrates. I plan on adding 12L to a 150 gallon tank with only two small clowns. No lights, and as hard as it is no added carbon source. What do you guys think? Would you change or add anything to this experiment?


Below is a few pictures of my tank when it was first set up and how it's looking now using these methods.

http://i.imgur.com/hY4V1oA.jpg
http://i.imgur.com/hxfdn6E.jpg

If you're interested here's a link to my build thread (http://www.reefcentral.com/forums/showthread.php?p=25113379#post25113379)

[Roggio]

It's also worth noting, I have two 4+ foot Zebra Moray Eels that eat large shrimps and fiddler crabs a few times a week and I have switched from using pellet foods to Nori and shrimp from Costco.

[homer1475]

Seachems Matrix media while great for normal nitrogen cycle bacteria, is not large enough, or thick enough to provide large anoxic zones for the bacteria that turn nitrates into nitrogen gas.

[bertoni]

I think a number of people have claimed that it worked for them. Why do you think the media is too small?

[homer1475]

It's my understanding that the bacteria that converts nitrates to nitrogen gas need large anoxic regions to grow. The matrix media is like the size of pea gravel. I would think being so small, oxygen would be able to penetrate it thoroughly thus not creating these anoxic regions.

I used it in my biocube, and never saw a reduction in nitrates from it's use.

[bertoni]

It's interesting that you never saw any results. Pea-sized might be good enough for nitrate reduction. I don't think we know for sure what the requirements are, but denitrification can be done by biofilms that have a nitrate-reducing organism growing under a layer of some other microbe. If that's a feasible process in our tanks, Matrix might work well enough. How much media did you use? I have heard plausible claims that Marine Pure is a lot more space efficient, which might account for your results.

[tmz]

The matrix is more kidney bean sized than pea sized. The pebbles actually float for a time. There seems to be plenty of internal surface area for microbes in low flow areas. I have no experience with the ceramic block,nor any data on internal surface area measures in the ceramic block vs the matrix pebbles.

[tmz]

As for vodka /carbon dosing. I've used it along with a little vinegar for about 9 years with excellent results in maintaining low ( less than 0.5ppm NO3) in a 700 gallon system. The bacterial supplements are not necessary; the heterotrophic bacteria are ubiquitous and will wax when an organic carbon source is provided. I've also used a sulfur dentirator in the past with excellent results in reducing nitrate.

[Roggio]

It's my understanding that the bacteria that converts nitrates to nitrogen gas need large anoxic regions to grow. The matrix media is like the size of pea gravel. I would think being so small, oxygen would be able to penetrate it thoroughly thus not creating these anoxic regions.

I used it in my biocube, and never saw a reduction in nitrates from it's use.

That's actually one of the main claims on their website http://www.seachem.com/matrix.php

There's a lot of reviews claiming it does just that. They also have a product called denitrate that's run in a canister under very low flow. All of this media is the same just differnt sizes. Pond Matrix is just larger Matrix.

It's interesting that you never saw any results. Pea-sized might be good enough for nitrate reduction. I don't think we know for sure what the requirements are, but denitrification can be done by biofilms that have a nitrate-reducing organism growing under a layer of some other microbe. If that's a feasible process in our tanks, Matrix might work well enough. How much media did you use? I have heard plausible claims that Marine Pure is a lot more space efficient, which might account for your results.

The matrix is more kidney bean sized than pea sized. The pebbles actually float for a time. There seems to be plenty of internal surface area for microbes in low flow areas. I have no experience with the ceramic block,nor any data on internal surface area measures in the ceramic block vs the matrix pebbles.

I'm actually running a Pond Matrix experiment on another thread if you guys are interested.

http://www.reefcentral.com/forums/showthread.php?p=25116752#post25116752

As for vodka /carbon dosing. I've used it along with a little vinegar for about 9 years with excellent results in maintaining low ( less than 0.5ppm NO3) in a 700 gallon system. The bacterial supplements are not necessary; the heterotrophic bacteria are ubiquitous and will wax when an organic carbon source is provided. I've also used a sulfur dentirator in the past with excellent results in reducing nitrate.

Very interesting, my system is around 600g total and I wouldn't be as into this hobby if I had to change 200$ worth of water each month.

The downside I see to vinegar is the PH drop and how much you have to use. I was actually pretty aggressive with vodka dosing and ramped up the amount pretty fast. from 5ml to 15ml within a month.

Are you saying the bacteria is moot after the initial cycle or all together? I've dosed a lot getting my system right in such a short time (very happy with Bio Spira) and considered dosing over the long run. I have Zeobak and I know a lot of those tanks dose on a regular basis. I have seen a few spikes of ammonia and dose a lot of bacteria as soon as it happens.

[tmz]

I use only 60ml of vinegar which in 700 gallons has very little effect on pH, I also dose 36ml of 80proof vodka daily. If it were just vinegar it would take 348 ml with would require very slow dosing to avoid a precipitous drop in pH when initially dosed. Both vodka and vinegar have an equal smaller long term effect on pH.

Bio spira may/may not actually provide some seed bacteria for autotrophic denitrification independent of the organic carbon dosing.

Heterotrophic bacteria multiply quickly in response to available organic C.

[Roggio]

I use only 60ml of vinegar which in 700 gallons has very little effect on pH, I also dose 36ml of 80proof vodka daily. If it were just vinegar it would take 348 ml with would require very slow dosing to avoid a precipitous drop in pH when initially dosed. Both vodka and vinegar have an equal smaller long term effect on pH.

Bio spira may/may not actually provide some seed bacteria for denitrification independent of the organic carbon dosing.

Heterotrophic bacteria multiply quickly in response to available organic C.

I was under the impression most people dose for denitrifying bacteria? Those strands can take anywhere from 10-20 hours to multiply?

I was able to get my system to cycle quickly using bacteria and ammonia. I added it until the ammonia hit 0 within a 24 hour period. I'm left with high nitrites and nitrates. After about a month of dosing vodka they hit near 0.

[tmz]

I don't think most use bacterial supplements for "dentrifying" bacteria.

In a given tank,there may be several types of chemoautorphic( they don't need organic C) bacteria involved in the ammonia oxidation process and aerobic denitrification process, including nitrobacter,nirosommonas, and nitro spira like species which occur naturally. So, depending on what's actually in particular supplement it may just increase the ammonia oxidizers/ nitrifiers or heterotrphic bacteria.

Some supplements may or may not actually contain viable strains of these types ;others may just be organic carbon with some viability for heterotrophic strains. In any case the bacteria are ubiquitous and will occur naturally.

When organic C is increased the heterotrophs flourish primarily using ammonia for a nitrogen source in a one step process. In other words they don't create nitrite or nitrate like the oxidizing autrotrophs do ;and compete with them for available ammonia. In time the reduction in nitrate poduction results in a reduciton in pre existing nitrate level

This thread may be of interest:

http://www.reefcentral.com/forums/showthread.php?t=2134105&highlight=organic+carbon+dosing

[Roggio]

Wow Tom, you were able to explain to me what countless hours of reading did not. Do you think these bacteria would die out quickly if they didn't receive the carbon source for a few days? Would this lead to a crash? How hardy do you think this bacteria is?

I just had some unbelievable results on a Pond Matrix test.
http://www.reefcentral.com/forums/showthread.php?t=2640680

[bertoni]

Most any bacteria will die or become inactive very quickly with a loss of food input. That's fine. Populations can increase very quickly, as well. A skimmer should be able to help with a population die off, although I doubt that anything much is needed.