Bacterial bloom with carbon dosing

[Newsmyrna80]

Hi all,
I'm about to throw in the towel. I have an established tank (over 8 years) and recently have discovered nitrates at 40. I have done massive water changes to no avail. I've added a new skimmer, macroalgae with no changes but I don't expect that after 2 weeks. In the mean time I'm moving corals in to QT tanks in the hopes of saving them.
I decided to try carbon dosing with vodka. I'm on my 2nd day of dosing and I already have a bacterial bloom. Stats: 80 gallon frag tank w/ 30 gal refugium. Estimated water volume 68 gallons. I dosed .125 ml (using a syringe) once in the morning and one at night. Now I have cloudy water. HELP!
What do I do? Stop dosing? Add carbon? Do a large water change? :headwallblue:
Thanks in advance

 

[bertoni]

The bacterial bloom should go away on its own. I would stop dosing and wait, although tuning the skimmer to produce a bit wetter foam might help. What symptoms are the corals showing? Have you tested for nitrite? Nitrite will confuse nitrate test kits.

 

[Newsmyrna80]

I did test for nitrite. It was 0. Hammer has retreated and the war coral is starting to like lift off at the edge if that makes sense.
I did turn up the skimmer to make more of a wet skim. I quit dosing for the time being. Fish was breathing ok so not too worried just yet on oxygen. The cloudiness did start clearing up.
Should I start dosing again tomorrow morning?

 

[Sk8r]

I would NOT dose again yet. A water change might be in order to help the inhabitants. You say you have a new skimmer. What brand? Type? Model? Size of tank? And how long have you run it before resorting to carbon?

 

[bertoni]

I would avoid more dosing for a bit here. I would add some fresh carbon and consider some water changes, given that the corals are having trouble. We need to find the source of the nitrogen. I'd stop feeding for the time being, and consider removing any bio-filtration media (slowly) and maybe consider removing the sand, which needs to be done carefully. Anything that might trap debris could be an issue.

 

[Michael Hoaster]

As a general statement, it appears that your biological (bacteria) filter has been overwhelmed by nutrient inputs. It may be that the overall system design has reached it's carrying capacity, and your best option may be to break down the tank and start over.

But it is important to find out the source of the problem, so you don't repeat it. Very long time without a water change? Did you add a medication/additive that could have harmed the bacteria? Does your system include known Nitrate factories like bio balls, blocks, etc? Do you run a bare bottom or very shallow sand bed? Do you habitually overfeed?

High Nitrate levels suggest that denitrification is not happening. Deep sand beds allow for a gradient of oxygen levels that will support diversity in bacteria types, including the ones that convert Nitrate to Nitrogen gas that simply bubbles out of the water.

What macro algae did you add? For your situation, you need a fast growing nutrient sponge, and that is ULVA. Plant it high up near the lights, and with those high nutrient levels you should see very high growth quickly.

Good luck!

 

[Newsmyrna80]

I would NOT dose again yet. A water change might be in order to help the inhabitants. You say you have a new skimmer. What brand? Type? Model? Size of tank? And how long have you run it before resorting to carbon?

I haven't dosed again. The water did clear up but I did a water change anyway and moved some of my corals into a QT tank. I'm going to do water changes in there to at least lower the nitrates in the QTs.
I got a RedSea RSK300 which is rated for 300 gallons and I have approx. 70 gallons of water between tank and refugium. I had been running it about a week. I know it's not that long but I was already getting skim mate from it.

 

[Newsmyrna80]

I would avoid more dosing for a bit here. I would add some fresh carbon and consider some water changes, given that the corals are having trouble. We need to find the source of the nitrogen. I'd stop feeding for the time being, and consider removing any bio-filtration media (slowly) and maybe consider removing the sand, which needs to be done carefully. Anything that might trap debris could be an issue.

I did do a water change and removed some of the corals. I haven't been feeding them but every other day (foxfish is ticked).
My tank is rather old I guess. I had started it 15 years ago but 7 years ago I upgraded. I did use the same live rock but only used 50% of the sand and then put new sand in.
So my thinking is to drain most of the water, remove all live rock, corals and critters and remove most of the sand bed. Refill the tank, test and if all is well put everything back in. Thoughts?
Thanks again for all the advice!!

 

[Newsmyrna80]

As a general statement, it appears that your biological (bacteria) filter has been overwhelmed by nutrient inputs. It may be that the overall system design has reached it's carrying capacity, and your best option may be to break down the tank and start over.

But it is important to find out the source of the problem, so you don't repeat it. Very long time without a water change? Did you add a medication/additive that could have harmed the bacteria? Does your system include known Nitrate factories like bio balls, blocks, etc? Do you run a bare bottom or very shallow sand bed? Do you habitually overfeed?

High Nitrate levels suggest that denitrification is not happening. Deep sand beds allow for a gradient of oxygen levels that will support diversity in bacteria types, including the ones that convert Nitrate to Nitrogen gas that simply bubbles out of the water.

What macro algae did you add? For your situation, you need a fast growing nutrient sponge, and that is ULVA. Plant it high up near the lights, and with those high nutrient levels you should see very high growth quickly.

Good luck!

No, I've been very diligent about maintenance as I've had a tank for 15+ years but I guess I have been overfeeding a foxface which was accumulated in the last couple of years (he's kinda demanding ). Also I acquired a pistol shrimp which has dug all under the rocks so I'm assuming he has released all the nitrates in to the water column. Not to mention the skimmer I had for years well for lack of a better term, sucked. I did finally go buy a new one.
I don't have a DSB in the main but I do in the center section of my refugium which has chaeto in it.
I don't have bioballs or any kind of filter floss.
I was hoping that carbon dosing and cutting back on feeding would be the answer as the persistent water changes have not made a dent. I may have to change out the sand bed and do a nearly 100% water change.
Fun!:celeb3::headwally:

 

[Michael Hoaster]

"Also I acquired a pistol shrimp which has dug all under the rocks so I'm assuming he has released all the nitrates in to the water column."

It seems unlikely that your sand bed accumulated Nitrate since that is where the majority of your bacterial filter resides. Maybe I'm missing something.

"…I have been overfeeding a foxface which was accumulated in the last couple of years (he's kinda demanding )."

Overfeeding your fox face for a couple years could do it. Have your phosphate levels gone up too? If so, you may have found the cause.

 

[Newsmyrna80]

"Also I acquired a pistol shrimp which has dug all under the rocks so I'm assuming he has released all the nitrates in to the water column."

It seems unlikely that your sand bed accumulated Nitrate since that is where the majority of your bacterial filter resides. Maybe I'm missing something.

""¦I have been overfeeding a foxface which was accumulated in the last couple of years (he's kinda demanding )."

Overfeeding your fox face for a couple years could do it. Have your phosphate levels gone up too? If so, you may have found the cause.

I've had him for a couple of years so I think that is the major cause. Phosphates are a little higher but not horrible. So given that this is the probably the reason I would think that doing a major water change would help but I've done several and it hasn't changed at all. Maybe removing the sand along with a 80% water change would take care of it. Thoughts??
Thank you

 

[bertoni]

I don't think that there's any point in removing the live rock. I'd just remove the sanded, and see whether that helps.

 

[Tcook]

Have you been vacuuming the sandbed for the past 7-8 years?

Sent from my SM-G965U using Tapatalk

 

[kharmaguru]

Also I acquired a pistol shrimp which has dug all under the rocks so I'm assuming he has released all the nitrates in to the water column.

Not released nitrates but potentially oxygenated the anaerobic denitrifying bacteria thus killing them off and in fact making it a "factory" instead. Unlikely (unless he's a really busy shrimp) but just throwing it out there.

 

[Newsmyrna80]

Have you been vacuuming the sandbed for the past 7-8 years?

Sent from my SM-G965U using Tapatalk

I do but I haven't been overly aggressive about it.

 

[Newsmyrna80]

Have you been vacuuming the sandbed for the past 7-8 years?

Sent from my SM-G965U using Tapatalk

I don't think that there's any point in removing the live rock. I'd just remove the sanded, and see whether that helps.

I was going to temporarily remove the live rock and put it back in after adding new sand but I like your idea better

 

[bertoni]

Exposing live rock to air can cause problems by killing organisms. That's fairly rare, but when the risk is easy to avoid, no need to take it.

 

[Newsmyrna80]

Exposing live rock to air can cause problems by killing organisms. That's fairly rare, but when the risk is easy to avoid, no need to take it.

Do you think it'll be ok exposed as long it would take to do a 90% water change? And do you think removing 1/3 of the sand bed as well as 90% water change will be detrimental? I want to take a big swing at these nitrates but don't want to cause a new cycle. Thank you again for all your help!

 

[bertoni]

I would avoid doing a large water change like that. Nitrate levels can bounce back so quickly that it's not worth the risk, in my opinion.

 

[Timfish]

Sorry to hear about yoyr problems! I would be doing larger water changes and start using activated carbon, GAC if not already. I also would definitely stop carbon dosing and I also would pull out the algae as research shows it's adding labile DOC that promotes unhealthy bacteria. Get a copy of FOrest Rohwer's "Coral Reefs in the Microbial Seas" (Kindle is $10 paperback is $20) Labile DOC, AKA Carbon Dosing can cause serious problems with corals and promote the proliferation of bacteria. If possible I would get some water from a "healthy" reef ssytem for water changes to help introduce beneficial bacteria.

My guess is your problem is not nitrates specificly but something else that has caused your corals to stop feeding. Corals prefered nitrogen source is ammonia and urea so if they stop feeding nitrates will go up as more of it is converted to nitrates. Cryptic sponges also can process DOC very quickly returning nitrates back into the food chain in short order. Hopefully moving your corals won't stress them out too much but don't be surprised if you see not only an increase in nitrates but also a big jump in hair algae in your system in the coming weeks. If possible I would be adding some hardy corals and polyps.