Nitrate issues

[paveking1]

Hi guys im going nuts i have a 220 oceanic reef tank been running 3 years , i have always have had nitrates at least 40 ppm .I do 50 gal water changes every 2 weeks tropic marin pro, i have 80 gal sump ae tech , skimmer ae tech ,75 gal refugium 6"sand bed in refugium,with a plenum under it. I have 1.5" sand in main tank with 400lbs live rock,my corals and fish are doing great even though its high ,I also use a 4 stage ro di unit with 0 tds . Any help would be great i would like to get them to 0 if possible.I only feed 2 times aday a little pinch for fish, corals 3 times a week. Thanks

[Kannin]

Just a thought... Each time you add new synthetic salt water to your tank, it has to go thru a mini cycle. 50 gallons of new water has to go thru a big cycle. I would do 25 gallons each week, creating a smaller cycle.

[paveking1]

Thanks i read that sugar/vodka thread im not going to do that & lose my hole system .I also tried smaller water changes that no avail.

[Tommy3492]

do a 50 gallon a week change, and what about the refugieum?

[Tommy3492]

oh sorry you do have a refugiem, you can always add more sand

[jab502]

Just a thought... Each time you add new synthetic salt water to your tank, it has to go thru a mini cycle. 50 gallons of new water has to go thru a big cycle. I would do 25 gallons each week, creating a smaller cycle.

That is not true. The water does not go through a cycle. The bacteria that could interrupt or start a new cycle are contained in the rock, not in the water, so your fine on water changes.

400 lbs is a tremendous amount of rock for that size of a tank. Is is possible that you have multiple "dead spots" because of the large amount of rock where water flow is unable to reach and allowing heavy amounts of detritus to build up?

Do you have macro algae in your sump? I had a similar problem and my trates went from 25 to 0 almost overnight with the addition of caulerpa and spaghetti algae in my sump.

[Kannin]

Originally posted by jab502
That is not true. The water does not go through a cycle. The bacteria that could interrupt or start a new cycle are contained in the rock, not in the water, so your fine on water changes.

400 lbs is a tremendous amount of rock for that size of a tank. Is is possible that you have multiple "dead spots" because of the large amount of rock where water flow is unable to reach and allowing heavy amounts of detritus to build up?

Do you have macro algae in your sump? I had a similar problem and my trates went from 25 to 0 almost overnight with the addition of caulerpa and spaghetti algae in my sump.

So... are you saying that I could set up a new tank with say, 100 gallons of newly mixed water with no sand or rocks and drop fish in it and they would be fine?

[LukFox]

Originally posted by Kannin
So... are you saying that I could set up a new tank with say, 100 gallons of newly mixed water with no sand or rocks and drop fish in it and they would be fine?

That's not what he's saying at all. If you have established sand and rock that already have all of the ammonia and nitrite converting bacteria living in it, then sure you can do a very big water change so long as the rock and sand aren't out of water for too long. There is an insignificant amount of free floating bacteria in the water, so taking a lot out won't do much unless you mess with something else. You do have to be careful with matching the parameters of the new water to the old though, as a lot of saltwater animals are sensitive to that.

[LobsterOfJustice]

Originally posted by jab502
400 lbs is a tremendous amount of rock for that size of a tank. Is is possible that you have multiple "dead spots" because of the large amount of rock where water flow is unable to reach and allowing heavy amounts of detritus to build up?

Agreed. What's your flow in the main display?

[tigereye37]

Better yet, what is your bioload in the tank? How many fish and what size?

[garygb]

Is your 6 inch sand bed in the refugium oolitic aragonite sand? Could detritus have built up there? Sometimes DSB's need to have the top inch or so siphoned. Does the sand in the display tank need to be siphoned? From what I've read, 1.5 inches might be trapping a lot of detritus, so I would siphon it. Have you considered a RDSB as discussed in a thread on RC? Do you have water flow sufficient to turn over the water volume at least 15 times per hour? How are your animals looking? Have you tested the nitrates with more than one test kit?

[paveking1]

I do have macroalgae in my refugium. fish there is 4 tangs 4 anthias a long nose hawk, golden angel and a fat mandrian. Flow consists of a bluline 100 2 tunze nanostreams ,2 hydros 4 behind rock.I do siphon top layer of refugium onc

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a month.