Cause of High Nitrates???

[JTN]

Hi guys,

Been outta the loop for a while but back now. I have a question that I pretty much already know the answer to but I want 2nd opinion (and 3rd and 4th, 5th, so on). My brother has a 45 gallon corner tank. He had about 10-15 lbs of LR in the tank and alot of "fake" LR. ($ issue). He is using a Jebo 828 or 528 canister filter. His Nitrates are skyrocketing. The last time tested I beleive more than 100 ppm. I have been telling him the nitrate problem is the "noodles" in the Jebo. Before he takes them out I wanted to post here to see if anybody else agrees with me. BTW.... I just added about 40lbs of "real" Fiji LR to his tank over the weekend. I had the offer to take the LR from a friend but figured he needed it more than I did so I donated all but 4 pcs to his tank.

So anyway..... The noodles. Should he remove them from the filter or no?

Thanks for the help guys.

Jim

 

[DaveK]

Nitrates in a reef aquarium come from a number of sources. In the system you describe there are several problem areas.

Since the system already has high nitrates, the first thing that needs to be done is multiple partial water changes. The system will need about 6 or 7 water changes of about 1/3 the water. Each one should be done several days to one week apart.

While your at it check the tap water for nitrates. This can be a major source of the problem. If that is the case, look into a RO/DI unit, but that is another subject.

Once you get the nitrates down you can start working on the other problems.

The first item you seem to have corrected. That is the 10-15 lbs of live rock. That's not nearly enough to be effective. The addition of 40 lbs of live rock gets the system to a reasonable amount.

Next check how much the system is being fed. Many people grossly overfeed. This is likely to be a major source of the problem.

Also check the livestock. Overstocking easily leads to nitrate problems. The old rule of one small fish per 5 gal of water is not hard and fast but a good place to start. Keep in mind that the 50 lbs of live rock displaces a lot of water. I would estimate about 15 - 20 gal. This means all stocking should be bases on a system that holds about 30 gal.

The use of canister filters on moderate size tanks is sort of a "necessary evil". I don't think anyone would argue that they are the best choice, but usually something better is not cost effective. The question then becomes, how do you get the most out of a canister filter?

In a modern reef system, the live rock provides the necessary biological filtration, so there is no need to put noodles or other bio media in the canister. Yes, you are correct, the noodles should go, but only doing that is unlikely to resolve the nitrate problem.

You want the canister filter to contain only mechanical filtration media, and optionally chemical filtration media, such as carbon. In addition, the canister filter should be changed once a week. Remember that anything trapped by the mechanical filter is still in the system until you clean it. All the filter did was gather it into one place.

In addition, if the tank doesn't already have one, I highly recommend a decent skimmer. It's one of the few devices that remove waste products, before the bio media, in this case live rock, has to break it down. I'll even go further and say that good skimming is even more important than the canister filter.

 

[Carlo]

I think DaveK answer is right on the money so I'll second his answer.

The only little thing I'll add is that you probably should remove the noodles but do so over a period of time. Remove a little bit each week when you do the water change. The reason for the slow removal is to not upset the bacteria in the tank. By removing it slowly you give the bacteria a chance to inhabit the liverock and sand without abruptly removing them all at the same time (the bacteria on the noodles).

Carlo

 

[AnDom1]

Dave and Carlo offer good advice...But you must add more live rock...Having said that, just be sure you do not add "raw" (uncured) rock.

Dom

 

[Erich]

I agree with everyone, except on the use of canister filters. Canister filters are nitrate magnets. The nitrates get stuck in the sponges and so forth and only are cleaned when the media is replaced or hand washed (For which you will lose a lot of good stuff also.). I suggest using a Sump with a protein skimmer to get a good amount of nitrates out. With a sump filtration you can still add a sponge or filter pad to weed out the big stuff, and easily replaced. The protein skimmer will skimmer the water on a continuous basis to pull more nitrate out. So basically what it sounds like to me that its a filtration problem and few water changes. Keeping to a water changing schedule is very important. I would suiggest 30% change, four days later 25%, the four days later 10-15% water change. The first water change will get alot out. You do not want to change to much to quickly as it will effect the delicate balance of the tank. Also a skimmer would help the situation also to filter out nitrates.
Remember this:

Water changes , water changes,water changes,water changes,water changes,water changes,water changes,water changes.

 

[Carlo]

Canister filters themselves aren't a nitrate sponge. It's only bad husbandry that causes the problem. They do their job very well by trapping debris in the water. It's up to the operator to clean the unit every 4 to 7 days.

You don't really have to worry about loosing any good bacteria in a canister because the "sought after" bacteria that break down nitrates aren't going to be there, but will be in low O2 environments like in the live rock and substrate.

The recommendation of a good skimmer is of course very valid. The more DOCs/organics that can be removed from the water before it has a chance to break down the better.

A series of water changes will lower the nitrates. Nitrates will drop approximately by the same amount as the water changes. For example doing 25% water changes and starting with 100 ppm nitrates will look like this:
After 1st water change: 75
After 2nd water change: 56.25
After 3rd water change: 42.19
After 4th water change: 31.64
After 5th water change: 23.73
After 6th water change: 17.80
After 7th water change: 13.35
After 8th water change: 10.01
That assuming the tank doesn't contribute further to nitrates in which case the results will be a bit higher.

So while water changes will help it's going to be best to solve the problem at hand causing the nitrates to be so high. He's already taken a few steps in the right direction by adding more rock which will allow more bacteria to colonize the rock and help break down the nitrates. He's (I'm assuming) going to be removing the noodles from the canister filter a bit at a time.

He could also use one of the nitrate reducing products on the market but I'd hold off on them for a bit yet until the tank has stabilized from the changes being made and I'd wait until a few water changes are under his belt first which will bring down the levels a lot.

Carlo

 

[DaveK]

... I suggest using a Sump with a protein skimmer to get a good amount of nitrates out. With a sump filtration you can still add a sponge or filter pad to weed out the big stuff, and easily replaced. ...

I've got to agree with Carlo on the subject of canister filters. They are not a nitrate factory, unless you fail to clean it.

While a sump and skimmer would be preferred, in this case we are talking about a 45 gal tank. A sump and skimmer would not likely be cost effective. You could end up spending as much on the sump, as you did on the whole rest of the system.

Now if the advice were for a much larger tank, say 100 gal or so, a sump based system would be ideal.