What do you do when carbon dosing doesn't work and you can't grow bacteria in your tank? Start over?

[schuby]

Can we back up a bit? You've said on here and another thread that your nitrates are 25-50ppm (not the 200+ in 1st post of this thread). What terrible effect do you believe 25-50ppm of nitrate is having on your tank? What has motivated you to take such desperate measures?

 

[2Wheelsonly]

After reading several articles on carbon-dosing (linked to by RHF), I've started dosing my tank. I'm no expert, but based on the articles, I think your tank has too low of a phosphate level. Others have been hinting at this but you are not biting. Do you know why your phosphate is so ultra low? Do you run GFO?

No GFO, may still be being absorbed by rocks. My po4 has been 0.02 for years but about 6 months ago I did notice it was extremely low and my corals lost color. Everything came back after I dosed and I dosed for about 3-4 months until it was stable again at 0.02.

 

[Dan_P]

I wish I knew the magic ingredient in my tank that's preventing any form of nutrient control.

I simply cannot lower my nitrates, I can't do it. People say "if the corals look great who cares" and my worry is that my nitrates are going up with no end in sight and I simply have no way to get rid of them. I have a 300G tank (350 volume) and decided these past few weeks to buy some 150G rubbermaid tanks. I filled 4 150G tanks with fresh mixed saltwater and test each batch (extremely slight pink almost clear which is expected with regular IO). I have a 6 stage RODI 150gpd unit with newer filters/membranes.

I just changed what I believe to be 600G of water over 7 days. My nitrates are the exact same and during that time my feeding has been so light that I feel guilty for my fish. I am giving my one anthia just enough frozen per day to survive and feeding the tank as a whole 1 time every other day and very small amounts. Nitrates are still dark pink on my test kits (nitrites are 0). Phosphates are sitting at 0.02.

I have tried carbon doing for the past year (as high as 220ml per day of vinegar) and I have 0.0 effect other than the most annoying problem of the foam blowing the lid off my skimmer and not going in the cup. The foam is so thick it blows the lid off the skimmer and if I tape the lid down it shoots air/water so violently through the hole in the lid it makes a mess. Literally 1 year of carbon doing and no effect.

I placed 4 no3 export bio bricks in my sump for surface area and nothing. I also have a sulfur denitrator (aquamaxx TS-2) with over 8 lbs of sulfur in it running for 8 months now and it's not even able to get to 15ml per min before going completely pink (these things are junk anyway so I don't look at this as a real solution, wasted my money on garbage).

My tank was started 5 years ago with live rock, since then added lots of dead rock to craft scapes but for the first 4 years I was always extremely low nutrient. I can only guess my tangs have grown in size over this time and my bio filter can't keep up but it feels no matter what I do I can't tackle this nitrate problem. I refuse to believe it's just in the water, SOMETHING is leeching nitrates, it has to. There is no other explanation.

I am debating tearing it all down and restarting with all new everything. I don't want to spend any $$ on livestock if I know the direction is headed right for a crash. My test kits are so pink I would assume I have 200+ no3 at this point as I just don't know.

A most frustrating situation!

The very first thing you must do is to actually measure the nitrate concentration in your system. without a measurement, you cannot tell if your nitrate reduction methods are working. Dilute the sample until the color is a lighter pink, a pink that is roughly in the middle of the color chart range. You could use RODI, this will give a slightly higher reading. This is fine, consistency is more important than accuracy for your situation. What you want is a reliable estimate that you can trend over time.

With regards to vinegar dosing, you probably did not go high enough. A 1 mL per gallon dose is roughly where you will observe heavy bacteria growth, significant change to skimmate, visible bacteria growth and rapid accumulation of slime or sludge in mechanical filters. Also, bacteria need phosphate to grow. The systems 0.02 ppm might have been sufficient, but that reading is at the ragged edge of phosphate tests and may actually have been lower. Increasing the PO4 wouldn’t hurt.

I assume you were running the sulfur denitrator and carbon dosing at the same time. I don’t think vinegar interferes with the denitrator performance. The denitrator might have been undersized or you quit using it too soon.

 

[Topekoms]

I would say it's the phosphate limitations on why you aren't dropping

 

[josephxsxn]

I agree with others here perhaps some phosphate will help. Your in the opposite situation I was in with my old tank and a sulfur denitrator; had no nitrate left to help consume phosphate.

Another thought (wild speculation) I had was perhaps somthing outcompeted some bacteria in your tank, have you tried dosing any bacteria additives recently?

 

[jt17]

No GFO, may still be being absorbed by rocks. My po4 has been 0.02 for years but about 6 months ago I did notice it was extremely low and my corals lost color. Everything came back after I dosed and I dosed for about 3-4 months until it was stable again at 0.02.

Given the range of uncertainty of our hobbyist grade test kits, .02 phosphate could actually be a zero. Many of the high end acro sellers (WWC, TSA, SBB to name few) are now keeping their po4 .1-.15.
Everything you’ve described sounds like you’re phosphate limited. A big tank like that should rarely have nitrate issues and your bioload is not that large. Like others have suggested, you might want to try dosing phosphates.

 

[((FORDTECH))]

[QUOTE="josephxsxn, post:

Another thought (wild speculation) I had was perhaps somthing outcompeted some bacteria in your tank, have you tried dosing any bacteria additives recently?
[/QUOTE]
How would you know this and how would you add it back. I think this might be my issue

 

[((FORDTECH))]

Another thought (wild speculation) I had was perhaps somthing outcompeted some bacteria in your tank, have you tried dosing any bacteria additives recently?

How would you know this and how would you add bacteria if low or gone ?

 

[josephxsxn]

How would you know this and how would you add bacteria if low or gone ?

I would give somthing like this a try from aquabiomics. Also checkout this thread they have a report in the post.

AquaBiomics

Microbiome testing for aquariums and aquaculture

aquabiomics.com

Just got microscope and something is killing fish

not Of course Nori too

www.reef2reef.com

 

[Stigigemla]

Going back to the basics.
Carbon dosing is a kind of growing bacteria. They need Nitrate, Phosphate, Carbon source and some other (very seldom limiting) elements to grow.
To get the bacteria (containing the nitrate and phosphate) out of the tank we need an appropriate skimmer.

 

[Streetcred]

This is one of those really odd things about reef aquaria and is reported quite often. In my case, I changed 50% of my small system's water and noticed the expected 50% drop in NO3, but within 2 days the nitrate level was right back where it started...with very minimal feeding during the time period.

Same ... I have 500gals and do 250gal fresh filtered NSW changes once a month ... 0.05ppm phos is my goal but I cannot contain the nitrates below 20ppm despite substantial vinegar dosing ... a little cyano from time to time but otherwise no excessive nuisance algae. For the past year I have been working on removing the sand bed, now about 70% gone.

 

[2Wheelsonly]

Same ... I have 500gals and do 250gal fresh filtered NSW changes once a month ... 0.05ppm phos is my goal but I cannot contain the nitrates below 20ppm despite substantial vinegar dosing ... a little cyano from time to time but otherwise no excessive nuisance algae. For the past year I have been working on removing the sand bed, now about 70% gone.

Have you noticed any change as a result of removing old sand?

 

[BrandonS]

Algae turf scrubber. A big diy one would be cheapish and help big time it sounds like.

How heavy do you feed?

 

[Uncle99]

Nitrate of 25ppm in a 5 year old tank seems about right to me.
Is there some reason you need to lower that?

The water changes should have had at least, a minor but noticeable effect on Nitrate.

It’s easy to be off 5-10ppm in any test.

This tank is 4 years old and runs N at 20ppm and phosphate .2ppm.

 

[2Wheelsonly]

Nitrate of 25ppm in a 5 year old tank seems about right to me.
Is there some reason you need to lower that?

The water changes should have had at least, a minor but noticeable effect on Nitrate.

It’s easy to be off 5-10ppm in any test.

This tank is 4 years old and runs N at 20ppm and phosphate .2ppm.

My SPS growth seems to have hit a snag and it started roughly around the time my nitrates started to rise (I always ran 5-10 nitrates). SPS corals don't grow, they encrust a bit and then lose color and just hit stagnant and eventually either die or look dead. I have some successes but not like 2 years ago when I would see growth overnight it seemed like.

I have lots of tube worms/vermatid snails deep below under my rocks. Could that be a cause of high nitrates? Again, without means to control it I am at the mercy of the unknown. If the number keeps rising, when does it stop? It's like a pressure cooker in the red as far as I am concerned.

 

[DanConnor]

No- vermetids don't cause high nitrates- they are removing nutrients. Your growth snag might have nothing to do with nitrate levels. I would get an ICP test and see if anything is out of whack.

 

[Reef - Tripp]

My recommendation would be a DND, I have installed 2 and it has always worked for me, lowering the no3 that passes through the reactor to 0.

Poor Man's Nutrients Control - Donovan's Nitrate Destroyer

Hello fellow reefers!. I have been in the hobby for more than 3 years, the first 2 years was tough. Cyno, diatom, nuisance algae, high NO3 (120ppm at one time) and ich/velvet. I have tried several nutrient control method (poor man, so most of it were DIY project). GFO, water fall scrubber...

www.reef2reef.com

 

[Scdell]

Raise your po4, slowly. Add Biodigest. Stop carbon dosing and all the nitrate reducing.
You didn't say whether you have a fuge or not. If not I'd add one. You're bacteria system is out of balance. You need to get it back on track. Do an ICP test. Make sure all the elements are right.