High Nitrates

[Neoz]

So my Salifert test kit finally came in. What a difference a quality test kit makes. So I tested my Nitrates 3 times in the last 2 days. They are not good. I'm reading 50ppm's. So here comes some questions.

Obviously I need some major water changes. I can only change out 30 gallons at a time. I know doing one large water change would be better but only have 1 brute can. So by the time I make it and let it sit for 24 hours that would be like 30 gallons every 3 days. Would that course of action be good enough?

Next question I'm planning on scaling back my feedings. Until I get my Nitrates in check would it be fine for the fish and corals to feed every other day once a day? Just looking for some suggestions to get my Nitrates in check asap. Or at the very least make them reasonable.

Just a FYI for those that don't know (most everyone here does) Tangs are some heavy poopers. Especially when you feed 2 times a day :hammer:

 

[Gary Majchrzak]

at 50ppm I'll bet you can grow Xenia and algae really well

 

[Piazzon12]

Are you feeding Nori/Seaweed... it can be very high in nitrates? You can definately reduce your feedings. If there's algae in the thank, the Tangs can pick at that. Unless you have certain corals that need target feeding, corals don't need to be fed at all. If you are feeding any coral specific foods (coral frenzy, marine snow) I'd stop that. If you are worried about it just stir the sand bed to feed the corals once in a while. Water changes will only have an immediate effect, and honestly aren't all that effective in the grand scheme. They are best utilized to suck detrius etc out of the sand bed. Skim wetter, you should have to change the cup every day. It will be a slow process so take a methodical approach, and dont expect to be at 10 ppm in a few days.
Other options include low dosage carbon dosing, but be sure to read up on in before you start.

 

[tmz]

Clean out detritus ; cut back on feeding;run gac;enhance skimming.BTW nori is not particularly higher than other foods in terms of phosphate to protein ratio.I use it every day and have PO4 at .04ppm and NO3 at 0.2ppm.

Beyond standard maintenance measures and water changes which I'd personally limit to 25% every few days, there are other ways to reduce nitrates including: denitrators( carbon or sulfur), polymer pellets such as N/P biopellets or the new Instant Ocean product, carbon dosing( vodka,vinegar, aspartic acid, glucose, etc.), more live rock and/or a functional sand bed.

 

[Neoz]

Believe it or not I don't have much algae at all. I believe my GFO Reactor and Tangs keep that in check.

Feedings have been cut and water changes will be stepped up for a while. Already running GAC. I'll admit I haven't been cleaning the sand like it should be. I'll vacuum that today as well.

Question, I'll be making some changes to my tank next weekend. Changing out almost all of my sugar fine sand to Special grade Reef sand. Also installing a different sump I just picked up.

In the sump picture below can the middle section be used for a fuge? Could I put a deep sand bed in there? If so how deep in inches? I have about 80lbs of NEW unused sugar fine sand still. Would that be better to use in the sump then the special Reef grade sand?

Sorry for all the questions. but I only want to do this one more time.. LOL

Picture of the sump. Of course it still needs cleaning.

....

 

[Piazzon12]

As far as the seaweed itself, it may not be high in nitrates, but I have soaked fresh seaweed in water for a few minutes, tested, and seen high nitrates... JME. Think about how it is farmed... probably growing in very nutrient rich, fertilized water, harvested and then dried.

 

[tmz]

Have you soaked other foods and tested?Wether it's grown in high nutrient water or not it still will only hold nitrate and phosphate in its tissues as it would in life. You've got a better chance getting excess nutrients form the packing water mixed in with frozen foods, in my opinion.

 

[tmz]

Neoz, Yes you could put an inch or two of sand in there or chunks of live rock .

When you change out your sand ,remember you will be removing a substantial part of your biofilter and may see ammonia spike. If it were my tank I'd try to remove it incrementaly over a period of a week week or two,then add the new sand seeded with a cup or two of the old.

 

[faze07hd]

Look into sugar dosing... I did a year or two back and have been 0 ever since!

 

[Neoz]

Tom thanks for the suggestions. Wouldn't I want a deep sand bed in my sump? I thought I read awhile ago that a deep sandbed has its advantages in a fuge. I can't remember for the life of me were I was reading that. Any thoughts there?

faze07hd, I'm just now researching vodka and or sugar dosing. I have to fully understand it before I even think of trying it. Thanks for the suggestions.

 

[faze07hd]

I researched both vodka and sugar. i found sugar to be much easier and just as effective. What i got out of it was that the sugar feeds the nitrates and it makes whatever nitrate particles in your tank big enough for the protein skimmer to pick them up. It went into much more detail than that, but that pretty much summed it up. Good luck!

 

[Neoz]

Do you still dose with sugar today even though your nitrates are 0? Or do you only dose when your Nitrates are on the rise?

 

[tmz]

I've tried sugar. Some corals( scolymia, lobophylia and others and anemones reacted badly. Closed darkened and receded in some cases. I've been dosing vodka and vinegar for 14 months. Works great without ill effects.

 

[tmz]

People used to think and some still do that a deep sand bed fed with filtered water even in a bucket would denitrify and that somehow the mere presence of sand would support the faculative( bacteria that use free oxygen and oxygen fixed to nitrogen ,ie nitrate)heterotrophic ( bacteria that do not use inorganic carbon and need a source of organic carbon)bacteria that perform denitrification. Indeed thinkingwasthat denitrification would not occur in shalow sand beds at all. More recent studies show that depth beyond an inch or so makes no difference in denitrification and that hypoxic areas(low oxygen areas) do form in shallow sand where these bacteria take the O from NO3 for energy via respiration.
Now if you add more sand as in depth you are certainly adding more surface area and it's likely to be hypoxic down deep, so why wouldn't a deeper bed remove more nitrate than a shllow one in the same surface area space.? Because the deeper sand is likely to be sterile without organic carbon or other nutrients unless there is a way to insure water movement down into it. In tank deep sand beds rely on live sand bed with benthic fauna to move it down via channeling activities. Advective current which occurs as flowing water hits obstructions in the water flow such as a rock stack causes a change in water pressure under the obstruction and a consequent upwelling and then downward flow. Diffusion which is molecular movement toward equilibriation within the water is very weak and will not move much if any organic and other nutrients deep into the bed .

The surface of the sand itself provides some obstruction. So it would be better to have a shallower remote bed with a larger surface area. Better still is a deeper bed of a few inches with structure on top of it such as a rock stack with swift current smashing into the rock.

In a small space like you have , I would use chunks of live rock since the water and nutrients are more likely to penetrate into its pores and channels than it would a deep dead sand bed or just an inch or two of fine sand.

 

[Neoz]

Great explanation Tom! Makes perfect sense to me. So rocks it will be. Still plan on having some cheato in there as well. I believe thats what its called. Still have to do my research there.

For the dosing Ill continue to do more reading of the pros and cons of each. The problem is there is soooo much information on both that it makes my head spin sometimes. Course that dosen't take much.....

 

[tmz]

The chaetomorpha will need light. If you go that way, I might just skip the rocks and just use some chaeto on opposite photoperiod to help with nutrient removal and night time oxygen levels and ph swings. The chaeto or other macroalgaes release exudates which contain nutrients and can build up on the rock and/ or sand and make a mess.

 

[tmz]

As far as the seaweed itself, it may not be high in nitrates, but I have soaked fresh seaweed in water for a few minutes, tested, and seen high nitrates... JME. Think about how it is farmed... probably growing in very nutrient rich, fertilized water, harvested and then dried.

Adam, Could you post the details of your test. I was skeptical that nitrate (NO3) could hang around throughoutthe drying process on the surface of the dried nori.

I took a 16 oz cup of water from my tank with very low nitrate(<0.2ppm) and added a a 2inch x4inch piece of 2 little fishes nori. I let it soak for 2 hours and tested the water for nitrates twice,once with an api kit which showed 0:fish1: nitrates and once with a slaifert kit which showed less than 0.02ppm. Absolutely no change.

 

[faze07hd]

I havent had the need to dose sugar for well over a year now. Nitrates still are at 0. I didnt have any bad effects on my corals at all. I tested daily and they went from 35ppm to 0 in about a week and a half. I still dosed very very small amounts occasionaly for a month or 2 and then didnt find a need to do so anymore.

 

[Piazzon12]

The seaweed issue may be dependent on "brands". Many people buy in bulk, and in most cases the seaweed is meant for other purposes (sushi, etc...). In my case it was no-name ebay seaweed.
When I first started having nitrate issues, I couldnt figure it out and was taking many steps to reduce them. I made the assumption that the seaweed was better than meaty foods, in terms of nitrate/phos, so I relied more heavily on seaweed for feedings. Eventually, I finally realized that the seaweed actually caused the Nitrates to get worse just hours after feeding. So I soaked a sheet in a cup of water for 5 minutes, tested with API, and registered very high nitrate.
I was taking many steps to reduce Nitrates, and I'm sure there were other causes as well in my case, but I found that the seaweed I was feeding was definately a contributor.