Nitrates

[kp1917]

Ok, I have a killer 65gallon reef tank w/ fish. Everythings pretty healthy but my nitrates are way high. Always have been. Do water changes and it stays high (up to 40). I wouldn't care but I can't keep shrimp alive.

Besides massive water changes, what can I do to get the Nitrates down?

[Wayupnorth]

In my experience the usual culprits are over feeding and underskimming.

[BLKTANG]

W hat type of substrate do you have? I had a problem with nitrates when i had crushed coral substrate,i got rid of the CC,& along with it went high nitrates.

[guyguerra]

I would work on the problem. Tanks look and do a lot better when nitrates are low. The first step would be to get aggressive on getting them down. I remember my first tank, and how high the nitrates were . I didn't think I could get them down, and never really did in that tank. When I upgraded I was determined to keep them down, and it worked. I bought a better skimmer, set up an easy way to do water changes and watched it closely. Once I got used to what it took to keep them down, it became easy. Once they get high, it takes a lot of work (water changes) to get it down, but then the maintenance isn't bad. You can do it.

[DaddyJax]

What kind of skimmer and filter are you using? how much/often/what do you feed?

[jeffbrig]

Originally posted by kp1917
Do water changes and it stays high (up to 40).

Besides massive water changes, what can I do to get the Nitrates down?

High nitrate suggests an imbalalnce between your bioload and nutrient export. A more powerful skimmer would help, by pulling more organics out of the water before they get converted to ammonia->nitrite->nitrate. On the other side of the coin, reducing the bioload (# and type of fish) or reduced feeding will help level things out. You can also grow macroalgaes in a refugium to help soak up nitrate.

[kp1917]

Thanks for all the replies:

1. I do have crushed coral out of the keys, shipped up here in water so it was never dry. I love it for all the critters. Wouldn't going to a bagged sand lose all the good stuff that my critters eat?

2. I only feed once or twice a day.

3. I'm using a prism skimmer but heard that the CPR BAK PAK is a better alternative.

4. I really want to go with a refugium. How much will that help?

Thanks again!

[Herbert T. Kornfeld]

What is your bioload? Also, how long has the tank been set up?

FWIW, a refugium wont help much, or as much as you might think. A better skimmer would be a big bonus. Also, you might want to cut back on feeding if you can. you would be shocked as to how little most everything in your tank can get by on...unless you have a very high bioload.

[kp1917]

I have an inherited six inch blue tang, a clown, six chromis, a small manderine, and a scooter blenny.

[BLKTANG]

Originally posted by kp1917
I have an inherited six inch blue tang, a clown, six chromis, a small manderine, and a scooter blenny.


The bio load is huge for 65g,IMO.A fuge will help considerably,but the main culprit is the CC,belive me when I tell you I know from personal expierence.When I had that stuff in my reef in the beginning I battled high nitrates for 2 mo,someone here on RC told me in these words "Get rid of the nitrate trap on the bottom of my tank"That's what I did,and it worked.

[teog]

I'm using a prism skimmer but heard that the CPR BAK PAK is a better alternative.

I have used both these skimmers and IMHO the bakpak is far superior to the prism. However both these skimmer are not capable to handle a 65g tank with medium or more bio load. You may want to look at the remora skimmers if your looking for a HOB. Or if your using a sump you can look at any of the needle wheel type skimmer, ie. asm, euroreef, etc

As everyone else mentioned frequent water changes and a better skimmer will help you out. also you mentioned you feed once a day, but how much? You want to make sure food is floating around for more than 5 seconds. I like to small amounts but I feed twice a day.

[Shark Bait100]

Hang in there, we all ran in the same problem. I could never get them below 20. I finally installed a 29 gal refuguim with chaeto and a deep sand bed , and seeded both sandbeds with garf grundge. I export phosphate and nitrates once a month by weeding out the chaeto. It has dropped nitrates to undectable. Oh, I run a large Bio load also, I like watching fish.

[kp1917]

A few more questions:

1. Definition for HOB; IMO; Chaeto; garf grundge.

2. Can I bury the CC? If so with what? If I have to get the CC out, what's the best method without polluting the tank? What should my substrate be?

Thanks

[Shark Bait100]

garf website
http://www.garf.org/algae2/janitor.html#grunge
Chaeto is short for Chaetomorphia
And I agree with getting a better skimmer. World of difference.

[MCary]

I don't see where you have any nitrate reducing system. Your skimmer, any skimmer, is not going to do it. The best a skimmer will do is remove some organics before they can break down. The rotting material in your crushed coral is going to produce Ammonia which will be broken down into nitrite which will be broken down into nitrate. At his point it will not be broken down any further and remain in the water column (with the exception of a small portion that escapes into the atmosphere as notrogen gas). The only bacteria that can utilize nitrate is anaerobic. That is, it cannot live in the presence of free oxygen.

So, if you do not have a refugium with macroalgae that uses nitrates as their source of nitrogen,r an anaerobic nitrate reducing reactor, a deep sand bed or in some cases a good anaerobic bacteria population in the core of large live rock then you either have to do frequesnt water changes or learn to live with high nitrates.

You can reduce your feeding, cut back on your fish, or dance the hockey pokie. You'll still have nitrates if you don't have a system to remove them.

Mike

[kp1917]

My sand bed is 3-4 inches and I have killer live rock from TBS, shipped submerged. How big of refugium, and what all do I need in it?

[kp1917]

So far it looks like I need:

1. New Substrate.
2. GARF Grundge added to said substrate.
3. A "real" skimmer.
4. A Refugium

Anything else???

[Airman]

The addition of a refugium will be a big plus. The bigger the better. You do have a large bio-load. Make a fish sandwich out of the 6 inch tang.

[Herbert T. Kornfeld]

and again, how long has the tank been set up?

[MCary]

Tampa Bay LR is not very pourous. I wouldn't think it would work well as a anaerobic bacteria harbor.

A deep sand bed in order to work depends on 2 things. Depth and grain size. Even if you have 4 inches of crushed coral, the grain size is too big to produce an anaerobic layer.

[kp1917]

MCary,

How much and what kind of sand should I add or should I remove the CC then add just sand?

Herbert,

The tank has been set up for alost two years now, but I moved it from a 50g to a 65g a few months ago.

[MCary]

The article I read suggested oolite or sugar sized sand to be the best. It also said that composition was not important. That silica sand worked as well as argonite. Personally I've used sugar sized sand and it worked as suggested. I could tell by the deep black layer of hydrogen sulfide. But snow storms (cloudiness from the fine grain) was a pain for the first 3 months. My watchman goby had the tank cloudy everyday by noon. he slept at night, it cleared up, then up in the morning to mess it up again.

[kp1917]

So you think that I should add a sugar sized CoraLife or simular on top of my 3 inchs of TBS CC?

[Herbert T. Kornfeld]

I found sugar arag to be a problem. It packs too dense, and that is the problem. All those black deposits means that the hydrogen sulfide is being trapped and deposited in the sand which is not a good idea. It clumps together when this happens, and then its a brick of crap. Is also is very hard to clean. Anything that causes enough motion to clean the dirt out (swishing in a bucket, vacuuming, using a powerhead to blow it around) also sends a cloud of sand into the water. And sediment and mulm gets too easily mixed in and impossible to seperate.

The claim that NNR can be achieved with as little as an inch or two of thickness is false...er...deceptive. Sure, it develops anaerobic bacteria with less thickness because of its packing density, but that also means that it can be disrupted that much easier, esp since it is so light. A hermit crab or goby across the surface can easily disturb & expose layers that are 1" below with this stuff, and you dont want that. That coupled with its poor 'breathing', and this substrate is my least favorite. That and the fact that out of every bag you get about 30% of it is dust that runs off when you clean it.

Silica is even worse. Its packing density is even higher due to its jagged, flat-sided structure (sugar arag is at least spherical in shape)...think broken glass, because thats pretty much what it is. Silica is harmful to sandbed critters because it can get lodged in and cut delicate tissues as they process it. Couple this with its inert nature, and that means that any NNR that happens in the substrate will end up lowering the whole aquariums pH since there is no nearby Calcium to buffer the byproducts of the NNR process.

My favorite stuff is that 2-5mm stuff that the arag-alive type bagged stuff comes with. Its a little bit larger than the sugar sized, doesnt create milky clouds, has a suitable buffer capacity, and is easy to clean and create a DSB/plenum with. I would add this to your existing crushed coral...but watch out.

It sounds like you have trapped alot of mulm and sediments in your crushed coral. It would be best to remove this by siphoning out the crushed coral as much as possible, giving it a good bucket cleaning with fresh water, and then return it to the tank. This way, your buying back some time with the nitrates until the sandbed kicks in with NNR. And then mix in some of that 2-5mm sand with your crushed coral...that should work perfect for denitrification and critters.

[Herbert T. Kornfeld]

I was just reading some of my reefkeeping books tonight to get all the info I could on nitrate reactors. In the Baensch Atlas #1, Hans talks about Crushed Coral, p. 86...

"Crushed coral was once frequently used as filter material in submersed filters and UG filters. It is cleaned so that no living bacteria remain, even though this material originates from the biotope of the aquarium inhabitants. Since, like synthetic materials, it has no buffering effect on pH's above 8.0, it is inferior to those materials. Likewise, the surface to volume ratio is less favorable.
Crushed coral used as filtration material or substrate is very frequently the cause of failure. Even today unclean material is repeatedly used, and it pollutes all of the aquarium water.
Prior to using crushed coral, the material must be tested for NITRATES! The material is covered with seawater (1 cup material, 1/4 bucket of water), left for one week, then the water is tested for nitrates. Even if only traces of nitrates are detected, the material is unsuitable and must be treated with sodium hydroxide and then wrinsed.
TODAY CRUSHED CORAL IS PROTECTED! That is reasonable, since it does not regenerate (not in sufficient amounts to 'mine' it).
Crushed shell/marble can be used instead. The nitrate test should also be performed when using crushed coral."

Sounds like the crushed coral itself might be the source of your problems...maybe you would be better off sucking it all out and filling back in with regular bagged aragonite sand. The nitrates might be from the substrate alone.

[bblundell]

Try AZ-NO3. It works