Batch vinegar dosing DIY

[karimwassef]

I have a 100 gallon surge that runs during the day on my 380gal DT. The surge are 20-30 gallons x 2 outlets. I have a 180gal sump, so to absorb the surge volume (up to 60 gal events), I have an aux sump that's ~100gal.

At night, while the surge is off, the aux sump is nearly full (surge container empty). There is nearly no flow between the DT/sump and this aux sump at night. I have a large valve that I can close to separate the two sumps and the DT/sump continues operating normally.

This also allows me to do ~100gal water changes by draining the aux sump and making a fresh mix from my 100gal RODI container. I can open the connecting valve so that the morning surge fill pulls the fresh water into the system.

Of course, during the day, the aux sump fills and empties opposite to the surge container.

Ok. Now. I rarely use this aux sump (large Rubbermaid container) except during water changes. So I would like to use this natural and automatic 100gal nighttime batch event to run a bacterial farm. I want to drip vinegar into this isolated sump water and turn on a pump to encourage bacterial growth through eggcrate plates hanging in the aux sump.

During the day, these plates will be exposed and covered as the surge events occur. The vinegar will only drop at night minimizing the vinegar flow into the main sump and DT. The nighttime batch event is ~9 hrs.

If the system description isn't clear, please let me know.

1. Will this work ?
2. Is 9 hrs enough?
3. Will the day surge compromise the bacterial batch at night?
4. How much vinegar should I dose into the ~80gal volume.
5. Should I dose it all at once at the beginning of the night or drip throughout the night?

Thanks

[karimwassef]

Aux sump

[karimwassef]

Surge tank

[karimwassef]

Main sump

[bertoni]

Does the sump have a protein skimmer attached? If not, the tank might get a large dose of bacteria, live or dead, in the morning. I'd make the the aeration is good, too. As far as dosing, you could try the standard tank dosing schedule to see how that works. Here's a link:

http://reefkeeping.com/joomla/index....arine-aquarium

[dartier]

Excellent question. I am also curious about how long it takes carbon dosing to run to completion for a given water volume.

My interest is on a much smaller scale, a converted zeovit reactor that is currently setup as a auto flushing flow through system, but after building a recirculating biopellet reactor, I got the idea that it may be possible to change to a recirculating style of reactor. This would allow the carbon and any other added nutrients (nitrate, iron) that may be required to process phosphate in an imbalance situation to be dosed directly in the reactor and allow much higher concentrations to be used.

I sort of did something along these lines by accident when my RS nitrate test went bad and read very low even though I was dosing nitrate. Long story short, my reactor grew a heavy amount of bacterial films, but since the reactor was a flow through, it raised the nitrate in the whole system. I expect by being able to contain the nitrate to the reactor, the level of nitrate can be raised to a high concentration and get a similar reaction as before.

Lets see what the answer is.

Dennis

[karimwassef]

The skimmer runs off the main sump, and is far from the aux. it's also off at night. I believe it helps the plankton culture.

There's no aeration in the aux sump, but I could add it by adding a penductor to my circulating pump and bringing it close to the surface.

I guess I'm wondering about the most efficient use of time and vinegar for a captive batch volume.

9 hours, 80 gallons, x? vinegar added in y? time.

Also, I don't know if the number of plates or direction of flow matters?

[karimwassef]

Based on the article, I should start at 15ml a day and start the dosing at the start of the night. Then up the dose to 60ml over 4 weeks.

Also, the current aux is full of amphipods. I didn't culture anything intentionally and I'm pretty rough in my salt mixing events: with about 4 inches of original tank water, I dump 2 bags (50gal each) in and then use a hose of RODI water to initiate the mix.

The amphipods are so tough, they literally swim through the thick brine!

[dartier]

Karimwassef, I am not sure if you have seen it, but you may want to look at the Natureef denitrator threads on here such as http://www.reefcentral.com/forums/sh...light=natureef as what you are proposing sounds similar to how the Natureef works. You can glean a bit of info about batch processing in those threads.

Dennis

[karimwassef]

Dennis - wow. Very relevant thread! They're doing some things differently but similar batch bacteria concept. They're doing minutes of batch vs. my hours and a small volume of water. They're also using methane instead of vinegar.

They want to reduce O2 while I was not focused on nitrates exclusively.

Lots to read so I'll dig in. Thanks for the lead.

[bertoni]

I suspect the bacteria will work very rapidly, maybe taking a few hours, but I am only guessing. I'd be sure to add a lot of aeration.

[karimwassef]

Hmmm. The thread focuses on anaerobic bacteria so they seal the tank and avoid aeration.

I didn't even think of that.

I'll start by building the bacterial hive first. I have a ton of bioballs (old school). Maybe I build an eggcrate cage with eggcrate baffles and fill it with bioballs!!

Then batch vinegar dosing and measure nitrates three times a day to see what the data says.

[karimwassef]

I'll have two different modes though.
1. During the night, the cage would be 100% submerged for 9 hours and with added vinegar.
2. During the day, the water level would go up and down every 4 minutes. Exposed for 4, submerged for 4mins. (I think). This wouldn't have vinegar.

In both cases, I wouldn't add air and I'll try to seal the vessel with plastic.

[bertoni]

If you seal the reactor, I'd at least aerate it very well before adding any of the water to the tank. There might be a lot of hydrogen sulfide in the water after 9 hours.

[karimwassef]

Interesting point. Should I add a one way valve to exhaust gas?
Is there a one way gas valve bigger than an airline?

[karimwassef]

If I limit the vinegar, would that limit the potential hazard for sulfide?

[iceet]

I don't think sulfide be a problem from vinegar unless you get a lot of die off for some reason. Also I dose 20 ml vinegar daily in my 80 gallon system

[Randy Holmes-Farley]

What is the advantage of trying to not let vinegar into the main tank?

Do you intend to have circulation in the sump plus vinegar at night? (I would, to minimize the potential for hydrogen sulfide)

[dartier]

Just to be clear, the reason why you are suggesting adding aeration is to avoid going going too anaerobic and having an underfed bacterial mass producing hydrogen sulfide.

The Natureef folks are actually trying to culture heterotrophic bacteria (pseudomonas sp) in anaerobic conditions for the purposes of denitrification. Which is not the traditional carbon dosing approach of using the growth of the bacteria as the export mechanism by the skimming/feeding to the corals of the bacteria themselves.

So aerating the vessel will limit the risk of sulfides, and also not tip the scales solely in favour of the anaerobic strains. This *should* allow for the greatest diversity of bacteria to be cultured, which hopefully means a faster cycle time or more production within a given period of time (E.g. 9 hours).

Dennis

[Randy Holmes-Farley]

Yes, there's no reason to need to push this sump into anoxic operation like a carbon denitrator, and aeration will oprevent that, and the more concerning possibility of anaerobic metabolism to produce hydrogen sulfide.

Aerobic consumption of the vinegar will work perfectly well to drive bacteria growth and reduce nitrate and phosphate.

[karimwassef]

Ok. I was planning on having a circulating pump in the aux sump but not aerate with bubbles. I can cover the tank but not seal it.

I don't think vinegar is inherently bad for the reef but in small doses. The idea of the reactor is
1. Reduce bacterial growth in the main tank system (localization)
2. Minimize the potential for pH reduction in the DT.
3. Allows the use of larger vinegar concentration (60ml vs. 15ml) in the aux tank (early evening) assuming it's consumption before the morning flush.
4. I already have an automated 80gal batch mode and I want to maximize its benefit.

Any ideas on using an eggcrate cage with bioballs as the reactor core vs. just eggcrate plates?

[karimwassef]

If this works, it should 'feel' like an 80 gal water change every night.
The bacterial gunk should be relegated to the removable caged media.
An actual water change (once every two weeks or a month) would be an export event as I rinse the media off with the old water-change export hose (cage in the garage sink getting washed off).

[karimwassef]

Side question - if aerobic bacteria are sufficient to consume NO3, why use denitrators at all?
Wouldn't vinegar dosing be sufficient?

[karimwassef]

One more: should I expect a sponge bloom in this reservoir's bottom?

[Randy Holmes-Farley]

Originally Posted by karimwassef

If this works, it should 'feel' like an 80 gal water change every night.
.

Only with respect to nitrate and phosphate, and only if it actually depleted it all in that time.

There are other reasons to do water changes.