5 GPD reverse flow 4" pumice bed, nitrate buster, denitratification

markstrimaran

Potamotrygon
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Nov 21, 2015
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Update.
1.5 gallon denitrator is going at 7.5 GPD.
Dosed with .33 CC sugar. When ORP MV hit -0

RFUG, Is at about 75 GPD. No sugar,
Nitrates at 7ppm. In tank
Nitrates at 0ppm out of denitrator.

Had a cichlid fight, lots of frayed fins.
Loaded carbon in pre filters for denitrater. And Rfug
The whole tank is getting treated. With Marden and Kana plex.

The 75 gallon project has started. NEVER USE PUMICE AS A FLUIDIZED MEDIA, It gets pulverized into milky mess. The poly filter canister Rocks at least. Great test.
 

markstrimaran

Potamotrygon
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Nov 21, 2015
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UPDATE: Silicate problem, diatomaceous brown stuff is growing. I am guessing that the pumice is leaching silicates.
Removed pumice from substrate, and spread the quartz sand over the UGF.
Loaded a filter sock in sump, and did a 25% water change. Vacuumed the sand. Then cleaned up sump filters. Lots and lots of detris.

The 1.5 Gpd denitrator is able to keep up with nitrates. The pumice by itself proved ineffective at removing any noticeable nitrates with out a carbon source.
The RFUG works great to quickly reduce nitrates from 100+++ppm to 15 ppm but it is not practical for long term use. I will tinker with just the sand for curiousness.
Please note: This tank is completely experimental. The 75 gallon is getting fitted in the basement with a state of the art low maintenance system.
back to work
 

markstrimaran

Potamotrygon
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Nov 21, 2015
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20160115_030331.jpg
Update.
Got a good picture of the sump, in the dark using my camera's flash.

I added a 2 liter sugar dosing IV Drip tank, on the top of the sump. Gives me 4 days of no maintenence.
All of the sugar dosing is done inside the anaerobic cylinder.
From left too right. Prefiltered pressurized Water is driped into, the bottom, of the the big canister. It flows up, at the surface it's open to the sump. Here sugar water is IV driped.
The next canister is completely anaerobic. Water goes to the bottom then seeps up.
From here it goes through 2 coffee filters in a 50 micron coffee basket. It catches most of the excess bacteria.
The water is then mixed with the flow coming out of the trickle chamber. It passes though a final poly fill before going back into the aquarium.
The flow is controlled with IV type roller cams, medical type, IV bag.
Dosing tank is set with 4cc dry sugar per liter, dosed at 300 ml/day.
I then regulate the aquarium water based on the ORP mv probe.
 

markstrimaran

Potamotrygon
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Nov 21, 2015
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Update:
Brown algae has stopped growing. Did a 5 gallon water change using distilled water, mostly to reduce silicate. A large WC would be better but then my nitrates would go up too 7ppm, as I am seeing how low they will go. Tank ppm at 4ppm.

Increased the flow to 15 GPD, Then had to remove a 1/4" tube. Replaced with 3/8" too handle the flow.

At 15 GPM @ 4ppm nitrate. The sugar dosing seems inefficient, as at 100ppm nitrate a cubic centimeter of sugar drops nitrates, about 30ppm. Probably a detention time issue.

Currently at 5ppm nitrate, flowing 12 GPD. I am going to hold the sugar dose at 1 cc per day/250ml solution, and not attempt to keep the discharge at 0ppm.
 

markstrimaran

Potamotrygon
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Nov 21, 2015
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Update.
The denitrator at 12 GPD, @1 cc sugar dose. Has balanced out and is removing all nitrates. It required 4 cc of sugar to remove all nitrates a few days ago. I am not sure what's going on.
I wife over feeds the tank, which also keeps the tank aggressiveness down. The filter can handle it. I think that perhaps it is providing an extra carbon source.
IT would be great if it would function on normally occurring carbon.
 

markstrimaran

Potamotrygon
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Nov 21, 2015
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Update.
Denitrator was fed 1cc of sugar per day, ORP mv meter was picking up nitrates in effluent. At -7 mv
Tank nitrate increased to10ppm by saturday.

24 hours ago I increased the flow to 20 GPD,
Filled the sugar tank with 2 cc sugar per liter.
Set the drip dose to hold, a posative +2 ORP mv.
Nitrates dropped to less than 5 ppm. And used 1.5 liters or 3 cc of dry sugar.

I am at max flow. I will need to replace the 1mm Iv tube, and get a small needle valve to go bigger.

I will idle the Denitrator to .5 cc liter and build my nitrate ppm. Then just dose once a week at 2cc.
 

markstrimaran

Potamotrygon
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Nov 21, 2015
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Update.
It took 48 hours at 20GPD with out any dosing, for it to start having a trace of nitrate in the effluent.
I am thinking that the bacteria have a method of storing the carbon source. When it is plentiful.
 

markstrimaran

Potamotrygon
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Nov 21, 2015
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UPDATE:
Nitrates are at 25ppm. I have not dosed any sugar in 10 days, and did two 25% water changes.
Tank ORP 49mv
Denitrator ORP 17 mv.

I will soon find out if the denitrator bacteria can survive 10 days without a carbon source. It was flowing 10 GPD for a while.

I just increased it to 20 GPD. I am going to feed it based on ORP mv readings.

Just an experiment. Too discover if it can remove a higher ppm nitrate, fast enough to keep up with a bigger bioload.
 

markstrimaran

Potamotrygon
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Nov 21, 2015
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It was slow to respond, but it is back up and running at 5 GPD. I will see how long it takes to reach 20 GPD. I am guessing about 24 hours.
 
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