Trying to keep Nitrates down...

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AdamHorton

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Joined
Aug 12, 2009
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Location
Cincinnati, OH
I have a 150 SW tank, it's been established for close to three years now and I haven't had too many problems with it. There are about 250 pounds of live rock in there right now -- I did a fishless cycle on the tank back in the day and the LR was in there during that process.

I've been having some issues recently with nitrates being pretty darn high. I should say that I haven't seen anything but a nice, solid ZERO for ammonia and nitrites since I first put fish in this tank, but for the past month or so, the nitrates have been so high that my test kit hasn't given me a very reliable reading. I've already started doing MASSIVE water changes (120 gal, where there is about 180 gal total in the system) but mixing up that much saltwater takes a while so it's a time-consuming process.

I'm starting this thread because I want to brainstorm ideas for how to keep my nitrates down. I know water changes can GET them down, but I want to KEEP them down -- I don't want to be doing regular 120G water changes. I'm not positive on the science behind a lot of this stuff and what will actually work.

1. Put less nitrates in the system.

OK, so if I (feed less)/(have less fish)/(have less biological filtration) that will reduce the nitrates I put into my fish tank.

- I feed 5-6 days a week what my fish will eat in 2 minutes.
- Current stock is 5 medium damsels, 2 medium tangs, a DW Goby, 2 Bangai Cardinals, and some Nassarius Snails.
- I have 250 lbs. LR and about 75 lbs. of live sand.

...I do not want to reduce the fish in my tank. Sure, feeding less is an easy thing to do, but will it matter if I don't reduce the LR in the tank?

I don't want to just start taking things out of my tank to reduce nitrates unless I know exactly what I'm doing; I thought the bacteria that live in the LR would just process whatever fish waste was created into nitrates, and the population of bacteria would adjust to how much fish waste was created, but is there more to it than that? What is the right plan of attack here?

Once my nitrates are down to a level where I can get some precise measurements (may be a couple of weeks before I'm able to execute that many WCs), I'd like to figure out exactly how many ppm-of-nitrates-per-day my current setup produces and maybe see what kind effects tweaking certain things will have...

2. Take nitrates out of the system.

Water Changes. Yeah. I know. Some routine maintenance is required -- or is it? I've heard that the most successful SW tanks don't require water changes for the purpose of keeping nitrates down, since other methods of nitrate export are able to regulate the nitrates in the system so well that they can stay below 5ppm without water changes.

Other methods of nitrate export:

Protein Skimmer - Well, I have one, and it certainly removes -- stuff -- from my tank, but is that nitrates? The skimmer I have is certainly "too small" for my tank, but it's the biggest I can fit in the little space I have for it, so improving this isn't *really* and option for me.

Algae Turf Scrubber - So this is a thing that some people have built... is there something available that isn't DIY? How effective is this?

Macroalgae - So this is where a good portion of my failure comes in. I've tried my very best to have some macroalgae in my refugium, but never have I gotten anything to show any growth, and if I understand correctly, if it's not growing, it's not removing nitrates from your system. Right now I have a ball of chaeto down there that I'm not sure is even alive at this point. I've tried asking around at LFS all over the place, and in the past year, they say they haven't been able to get their hands on the stuff. I can order it online, but I'll pay like $50 for a couple of golf ball-sized chunks that are half dead when they get here. I've heard anything other than chaeto could be dangerous for a tank. If there's something about an effective macroalgae setup that makes it work, I guess I'm missing it. If this is a really effective way of nitrate export, maybe we should debug my setup?

Smart people: thoughts?
 
Look up turbos aquatics, he has amazing algae scrubber, build quality is excellent, can't be beat. This is the solution that I would choose if it were me
 
I have a 150 SW tank, it's been established for close to three years now and I haven't had too many problems with it. There are about 250 pounds of live rock in there right now -- I did a fishless cycle on the tank back in the day and the LR was in there during that process.

I've been having some issues recently with nitrates being pretty darn high. I should say that I haven't seen anything but a nice, solid ZERO for ammonia and nitrites since I first put fish in this tank, but for the past month or so, the nitrates have been so high that my test kit hasn't given me a very reliable reading. I've already started doing MASSIVE water changes (120 gal, where there is about 180 gal total in the system) but mixing up that much saltwater takes a while so it's a time-consuming process.

I'm starting this thread because I want to brainstorm ideas for how to keep my nitrates down. I know water changes can GET them down, but I want to KEEP them down -- I don't want to be doing regular 120G water changes. I'm not positive on the science behind a lot of this stuff and what will actually work.

1. Put less nitrates in the system.

OK, so if I (feed less)/(have less fish)/(have less biological filtration) that will reduce the nitrates I put into my fish tank.

- I feed 5-6 days a week what my fish will eat in 2 minutes.
- Current stock is 5 medium damsels, 2 medium tangs, a DW Goby, 2 Bangai Cardinals, and some Nassarius Snails.
- I have 250 lbs. LR and about 75 lbs. of live sand.

...I do not want to reduce the fish in my tank. Sure, feeding less is an easy thing to do, but will it matter if I don't reduce the LR in the tank?

I don't want to just start taking things out of my tank to reduce nitrates unless I know exactly what I'm doing; I thought the bacteria that live in the LR would just process whatever fish waste was created into nitrates, and the population of bacteria would adjust to how much fish waste was created, but is there more to it than that? What is the right plan of attack here?

Once my nitrates are down to a level where I can get some precise measurements (may be a couple of weeks before I'm able to execute that many WCs), I'd like to figure out exactly how many ppm-of-nitrates-per-day my current setup produces and maybe see what kind effects tweaking certain things will have...

2. Take nitrates out of the system.

Water Changes. Yeah. I know. Some routine maintenance is required -- or is it? I've heard that the most successful SW tanks don't require water changes for the purpose of keeping nitrates down, since other methods of nitrate export are able to regulate the nitrates in the system so well that they can stay below 5ppm without water changes.

Other methods of nitrate export:

Protein Skimmer - Well, I have one, and it certainly removes -- stuff -- from my tank, but is that nitrates? The skimmer I have is certainly "too small" for my tank, but it's the biggest I can fit in the little space I have for it, so improving this isn't *really* and option for me.

Algae Turf Scrubber - So this is a thing that some people have built... is there something available that isn't DIY? How effective is this?

Macroalgae - So this is where a good portion of my failure comes in. I've tried my very best to have some macroalgae in my refugium, but never have I gotten anything to show any growth, and if I understand correctly, if it's not growing, it's not removing nitrates from your system. Right now I have a ball of chaeto down there that I'm not sure is even alive at this point. I've tried asking around at LFS all over the place, and in the past year, they say they haven't been able to get their hands on the stuff. I can order it online, but I'll pay like $50 for a couple of golf ball-sized chunks that are half dead when they get here. I've heard anything other than chaeto could be dangerous for a tank. If there's something about an effective macroalgae setup that makes it work, I guess I'm missing it. If this is a really effective way of nitrate export, maybe we should debug my setup?

Smart people: thoughts?

Try a biopellet reactor their pricey tho but if you get the right size very effective
 
When doing your water changes, aim a power head at the rock and kick up anything loose on it or in low flow zones. These are areas that can pollute the tank if not addressed.
You could also try a sulfur denitrator. If set up correctly (2 chambers, 1 with sulfur media and the second with crushed coral), it will knock nitrates down very quickly and keep them down.
 
Do you have a light in the refugium? Cheato doesn't need great light to grow, but does need some light.
If you have no room in your sump for a bigger skimmer, you could add a hob skimmer to help remove the waste before it turns into nitrates. Aqua c remora hob skimmer works great for me and is quiet.
You don't seem to have a huge fish population, but you could be feeding too much. How much are you feeding?
 
I use one cube of frozen food each time I feed, along with some dry pellet food. It takes them about 2 minutes to eat it. I'm not sure how to describe it more precisely than that -- any suggestions? (I might be able to type the labels of each product here once I get home tonight if that helps)

There are a lot of suggestions for products on here that I haven't heard of. While this is great, a quick Google search (without digging terribly deep) of them doesn't really lead me to anything that tells me how they work. I also don't get much in the way of how effective these methods are considered to be, aside from a couple of threads where people post anecdotal stuff.

How would a guy like me go about figuring out which of these methods would be best for my tank without just buying them all and trying them? I'm not afraid of doing my homework and figuring out how they work, but I'm having trouble even getting to that point...
 
One frozen cube plus that many pellets, how often? If you put a weeks worth of food in your hand, how full would your hand be?
Are you taking the equivalent of that out with skimming, water changes and such? If the answer is no, you are feeding too much and/or you aren't exporting enough nutrients. Everything you put in the tank must be removed, by you. Just because a cube of food disappears, doesn't mean it's gone.
 
Also, there's Live-plants.com and they sell cheato for $10 each, and shipping is $15. They have lots of plants to chose from. I've not personally use them, but I've heard good things about them.
Adding some plants like shaving brush or saltwater fern would help with nitrates too.
BTW, what brand test are you using? API runs higher IME.
 
It is an API test kit.

I took the liberty of measuring the amount of food I put in the tank tonight:

1/4 tsp of New Life Spectrum Marine Fish Formula
100g cube of Mysis OR Spirulina (alternating nights)
also 4 (1 inch by 2 inch) sheets of green nori and 3 sheets of the same, but red algae.

They are fed either 5 or 6 nights each week. It takes about two minutes for them to eat this much food.

I'd certainly be open to other types of plants -- I've heard that there are tons of potential problems with outbreaks and stuff if you don't go chaeto. Not sure where I heard that, but is there any wisdom to it?
 
I've heard of problems with grape caulerpa in the fuge. But I've not heard of problems with plants like shaving brush, saltwater fern, halimeda (money plant).
Whatever your result is for API, divide it by 4 to get the real number. As I said, API runs higher.
 
Divide by 4? Jeez, that's a touch drastic. You sure?

At least it makes me feel a little better about my current nitrate readings. Maybe off-the-chart isn't so off-the-chart...
 
I used to use API. I read on here that it says in the API instructions (which i didn't have any more) that API reads total nitrate, which most tests don't do, and that the results need to be divided by 4.4. Im no expert in this matter, but if you search API nitrate test on this site, you should get a bunch of results to read about this.
Then I bought a Red Sea test and I did multiple side by side tests and the Red Sea was always 4 times less. So I stopped using API nitrate.
But that's just me. And it's worked for me so far. :)
 
Here is a pic of what manual says
 

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That seems like important information. I'm a little embarrassed to have missed it. Thanks to both of you.

So after last night's little demonstration, I noticed that I'm actually giving more frozen food (at least by volume) than dry food. Then I realized that I'm just thawing the cube and putting the whole thing in, juices and all. Apparently that isn't the best thing in the world to be doing.

So I guess what I should be doing is straining out those juices after thawing, before it goes in the tank. How do people do this? I'd be worried that even my finest wire strainer would let some of those delicious morsels through (and my fish would never forgive me for that). Is that the solution (and I need to do this out of sight of the fish tank) or is there something better I can do?
 
Strain it with a small mesh fish net. I have white mesh ones that really barely has holes, small pieces can't get through. :)
 
That seems like important information. I'm a little embarrassed to have missed it. Thanks to both of you.

So after last night's little demonstration, I noticed that I'm actually giving more frozen food (at least by volume) than dry food. Then I realized that I'm just thawing the cube and putting the whole thing in, juices and all. Apparently that isn't the best thing in the world to be doing.

So I guess what I should be doing is straining out those juices after thawing, before it goes in the tank. How do people do this? I'd be worried that even my finest wire strainer would let some of those delicious morsels through (and my fish would never forgive me for that). Is that the solution (and I need to do this out of sight of the fish tank) or is there something better I can do?

While it is true that straining frozen food can cut down phosphates, the amount that it cuts it extremely minimal. There has been a long thread on this either at reef central or the reef tank forums. Basically the conclusion to many measurements concludes that the amount you are removing is around .0003 ppm phosphate. Which is a fairly insignificant amount of phosphate in the big scheme of things. The food itself produces far more phosphate after decomp.

So yes straining food can make it cleaner however its up to you to decide if it worth your time and tank to remove such a small amount.

Myself personally, i stopped straining frozen food a couple years ago with no ill effects or repercussions.
 
Feed less and upsize that protein skimmer. When in doubt it's always better to go +1 on filtration than not to have enough.

Also, I have found that biopellets in a reactor can drastically reduce nitrates. But add the biopellets a little at a time or you can start a bacteria bloom that can do damage to fish and inverts (it happened to me). I've had great results with Two Little Fishes NPX Bioplastics in their Phosban Reactor 150 in my 38 gallon system.

Keep in mind that the biopellets work in conjunction with the protein skimmer. In my experience it is extremely difficult to have a successful reef with low nitrates without an effective protein skimmer.
 
I should clarify my situation a bit:

Right now the tank is FOWLR. I originally had plans for a reef, and it would be great to get there one day, but if I can't get the levels to somewhere reasonable and keep them there without excessive maintenance, then I may just pass on corals and maybe get some more aggressive fish down the road -- someone should just tell me now that it's not feasible to have cuttlefish at home :p

My protein skimmer is a Tunze 9006.

Tunze Comline DOC Protein Skimmer

It says it's rated for up to 158 gallons, and there are about 180 total gallons in the system, but it's much smaller than other skimmers (that's why I got this one). It works quite well (after a little bit of tweaking) and will produce a nice cup full of nasty stuff every week or so, but is it "adequate?" I don't know. Unfortunately, if I wanted to beef up my skimming, the best I could do is maybe cram another Tunze (maybe the same size? It might be kind of tight) into my sump, right next to the other one.

In fact, all of the specs on my tank(s) are on this page:

Tank Specs | Adam's Flog

It's up to date except for the fact that the chaeto isn't really any significant size anymore, I don't feed every day anymore, and I'm on the massive-water-change-as-often-as-possible schedule instead of once a week. The video on that page shows the area under the tank decently well, which is all I have to work with in terms of space for extra stuff.

I did a quick search on Google to find out how Bio Pellets work, since many people have suggested them. I found this, which used little words that I could understand!

How Do Bio-Pellets Work? - Blogs - Reef Addicts

So if this is what I have to work with, and this article is mostly accurate, I should have enough skimming power to at least have *some* bio-pellets that will work at least a little bit, right? Correct me if I'm wrong, but if I follow this Start-Small strategy, I'll just get to the point eventually where it will do as much good as it can and then I stop, right? So my questions are:

How do I tell when to stop and/or if it's not working right?
Can I put this thing right by my skimmer? Should it be completely submerged?
 
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