Phosphate and Nitrate problems in big reef

[cellowithgills]

I've just started working with a tank that is approximately 1200 gallons in total volume. When I first started working with the tank, the owner was running a Model 3 Dialyseas Unit, which we have now removed and are going to be going back to constant water changes at the rate of ~25 gallons per day via a LiterMeter setup. When I started with the tank I started a testing regiment. Doing this, I noticed an alarming increase in PO4 in a fairly short amount of time. It went from .56ppm to 1.12ppm between 1/4/13 and 1/11/13. Of course, I started on GFO and also decided to try a phos-sponge to get the levels down to workable levels. From 1/11/13 to 2/1/13 the levels were lowered to .11ppm where I thought we could use GFO to lower them more and keep them low. However, this has not been the case. Since the first of the month when I stopped running a phos-sponge, the PO4 levels have risen to .47ppm. I will admit, it is likely that the testing was not as precise as it could have been in the beginning. But my results have been confirmed by using an online water testing resource.
To make the second part of this short; the nitrates are consistently over 25ppm.
At this point, I'm looking for solutions to control nitrates and phosphates. I'm considering looking into a DIY sulfur denitrator because he has a large GEO calcium reactor sitting around. I think that switching to a water changing system will do a lot for the system but I'm not convinced that it will be enough to keep all levels down. I'm looking for suggestions. Let the questions come, I will answer to the best of my ability.

[celamb89]

Have you looked in to carbon dosing? Maybe try adding a refigium with chaeto and/or algae scrubber as we as more aggressive skimming.

[cellowithgills]

He currently has a DSB with about 20 mangroves and a ~2'x2' section of his sump growing chaeto like crazy. His skimmer is, I believe, more than sufficient but we are looking into have a cup with a shorter neck built so that he can achieve a wetter skimmate. His skimmer is made by Aquarium Engineering and is about 8' tall and holds around 120-150 gallons if I had to guess. It's a nice skimmer but unfortunately with the current set up we can't adjust the water level any higher.

[cellowithgills]

Looking for other options that carbon dosing first, btw.

[bertoni]

GFO should be able to solve the phosphate problem, but it might take a lot of media. More light to the algae, more harvesting, or more area for it to grow might help. Those are the easier ideas to try, I think.

[mess7777]

There is likely a lot of phosphate bound in the substrate and rocks that will come out for a long time. You will have to be very aggressive for a long time until it stops spiking so easily. It could take months.

I would suggest an ATS to help out, this worked well for me.....but this is a pretty big project for a 1200 gallon tank!

As others suggested more frequent harvesting of chaeto may help speed things up. Randy has suggested that dosing iron can help chaeto to grow faster and may speed up it's growth and therefore nutrient uptake.

[keithhays]

I've just started working with a tank that is approximately 1200 gallons in total volume. When I first started working with the tank, the owner was running a Model 3 Dialyseas Unit, which we have now removed and are going to be going back to constant water changes at the rate of ~25 gallons per day via a LiterMeter setup. When I started with the tank I started a testing regiment. Doing this, I noticed an alarming increase in PO4 in a fairly short amount of time. It went from .56ppm to 1.12ppm between 1/4/13 and 1/11/13. Of course, I started on GFO and also decided to try a phos-sponge to get the levels down to workable levels. From 1/11/13 to 2/1/13 the levels were lowered to .11ppm where I thought we could use GFO to lower them more and keep them low. However, this has not been the case. Since the first of the month when I stopped running a phos-sponge, the PO4 levels have risen to .47ppm. I will admit, it is likely that the testing was not as precise as it could have been in the beginning. But my results have been confirmed by using an online water testing resource.
To make the second part of this short; the nitrates are consistently over 25ppm.
At this point, I'm looking for solutions to control nitrates and phosphates. I'm considering looking into a DIY sulfur denitrator because he has a large GEO calcium reactor sitting around. I think that switching to a water changing system will do a lot for the system but I'm not convinced that it will be enough to keep all levels down. I'm looking for suggestions. Let the questions come, I will answer to the best of my ability.

If you run enough BRS GFO reactors the PO4 will come down.
On nitrate and sulfur denitrators, I have just finished researching and testing on a small scale(300 gallons). First recirculation is not effective and does absolutely nothing for this process. Don't worry about the container being sealed from the air, it is the bulk of sulfur and slow flow that is responsible for the low oxygen areas.
For a 1200 gallon system you will need at least 12 gallons of sulfur or 1% which is the minimum required and will give you 12 gallons per hour through the system. For this system, which seems have issues, I would likely go with 2% sulfur and adjust the flow between 12 GPH and 24 GPH as the nitrate goes lower. The sulfur denitrators work very well and it only takes a couple days to two weeks begin seeing about 1ppm nitrate in the effluent, but it does require the correct bulk of sulfur to be effective...and about 1/4 to 1/3 of the amount of sulfur in calcium carbonate (arragonite) will be required to raise the PH of the effluent. It is going to dissolve it quickly so coral skeletons could be a problem if they picked up impurities as they grew.

Also, the amount of calcium/alkalinity used is roughly equivalent to what is released so it generally doesn't affect (help or hurt) this aspect as long as you have enough of it to buffer the effluent.

[mcgyvr]

funny no one asked about his feeding schedule/amount.

[csauer52]

funny no one asked about his feeding schedule/amount.

Or livestock for that matter.

[keithhays]

I would suspect that livestock amounts aren't likely to change for an owner of a 1200 gallon tank except possibly up. 25ppm seems like a steady state for a well fed tank without enough denitrifiation and po4 reduction systems in place likely because of the dialyseas system was in place. Contrary to popular opinion starvation isn't a nitrate control mechanism.

[csauer52]

I would suspect that livestock amounts aren't likely to change for an owner of a 1200 gallon tank except possibly up.

True, but my statement was in the context of *what* is in the tank. In the case of a 1200 gallon tank, there's plenty of room for big fish which would impact *what* is being fed and how much on a daily basis.

The needs of a shark for example are larger than those of smaller reef fish. That's what I meant.

[keithhays]

True, but my statement was in the context of *what* is in the tank. In the case of a 1200 gallon tank, there's plenty of room for big fish which would impact *what* is being fed and how much on a daily basis.

The needs of a shark for example are larger than those of smaller reef fish. That's what I meant.

Fair enough, plus we needs pics if there are sharks. :)

[csauer52]

^^ +1 :)

[cellowithgills]

The tank itself is 750 gallon. There are around 12 Tangs, maybe more, and a bunch of other reef safe fish including about 50 chromis. At this point he's feeding Rod's every other day and feeding nori either daily or every other day. He's currently running Avast Marine reactors, they're much bigger than the jumbo BRS reactors. Good to know about the denitrator, didn't know it would require that much media.

Sent from my ADR6350 using Tapatalk 2

[keithhays]

The jumbos only hold 6 cups of media depending on whether you are running high capacity or not, you will need either 9 cups high capacity or 19 cups normal capacity. And that just BRS' recommendations, I normally run twice the normal amount to stay within range.

CORRECTION: I just realized I am running twice the high capacity amount. :)

[nanotank]

This is your answer to controlling po4 at a much cheaper cost.

http://www.amazon.com/SeaKlear-SKZ-U-Q-Phosphate-Remover/dp/B0017SV6HU/ref=sr_1_1?ie=UTF8&qid=1360612701&sr=8-1&keywords=sea+klear

Do a search here for seaklear lathanam chloride and there is a great 36 page thread detailing its use over 4+ yrs. Easily the cheapest option for po4 removal though to a point then gfo or other means can be incorporated.

Peace

[nozleman]

Just hook up a giant media reactor running pellets and both your Nitrate and phosphate will go down!!! Very easy solution for your problem!!!