High Nitrates why? why?

[AI]

I am currently having serious difficultly controlling Nitrates in my Fish-only aquarium. My tank specs are as follows:

200 gallon tank
175lb crushed coral
75+ lbs. of live rock
Amiracle wet dry w/ 2 overflows SR-200
-----bio-balls, block sponge drip plate etc.
ETS Evolution skimmer 500 series

Aquarium receives a 60 gallon H20 change every 2-3 weeks. My problem began about 3 mos. ago when I moved the aquarium from one room in the house to another. The system was without power for about 45 minutes and after being set back up again it re-cycled. I am not sure why it had to cycle again because the gravel never dried and the water was saved except for the usual 60 gallons. I lost:

Emperor Angel
Dog face puffer
pair of percula clowns
Powder blue tang
Yellow tang

these fish were lost during the second cycle and after another month i began to slowly add fish again. Now the nitrates are 80ppm+ and the gravel has absolutely nothin left to vac and all sponges are completely clean. Why is this? Feeding is minimal. fish load is minimal (2 wrasses). After large volume water changes I cannot lower them. They will drop 30ppm then soar again. I use instant ocean salt and have used various test kits.. Any help would be appreciated.....Thank 8O s

 

[danmhippo]

Have you tested the source water used to mix salt mix? Test it for Nitrate and phosphate. If it's RODI water, test it anyway to see if the cartridge need to be changed. Many city water are high in nitrate, plus food you add to your tank, nitrate are indirectly being accumulated. Also, your setup is a very efficient nitrate factory, wet dry, CC, sponges, all are very efficient of converting raw waste into nitrate. The bigger the surface area for nitrifying bacteria to colonize, the faster raw waste are converted into nitrate. Unless you have nutrient export measures to reduce nitrate, you will always have this problem with your tank.

Do you have room to setup a 48" long sump with 6" fine sand DSB?

 

[naesco]

IMO your tank wants to cycle again and you wont let it.
Please remove the fish to a LFS or friends and 2 months after it is finished cycling add one fish per month until your fish are back again.

 

[IcantTHINKofONE]

I don't like giving advice cuz I don't really have any to give LoL. I'm a newbie. But I was expecting people to suggest AI remove his crushed coral and add a DSB. Wouldn't this help remove nitrates better than the crushed coral?

Edit: Re-reading Dan's reply, he did mention it but not directly. I dunno...that's what I would think would be best.

 

[Anonymous]

Your wet/dry is designed to convert NO2 into NO3 (and it does this very well). You've got a kicking NO3 introduction rate due to this, and a very low removal capability. LR will convert some NO3 into N2 gas bubbles, as does a Deep sand bed, but it has a very low capacity. If you want NO3 to be lower, either find a way to lower the introduction rate (lesser bio-load, get more LR, install a DSB and remove the wet/dry) or find a way to increase your removal rate (Deep Sand Bed, Macro Algae, more waterchanges).

CC substrate doesn't have the same kind of life in it that a sand bed does--it tends to trap and collect detrious rather than process it. When you moved, it probably released a bunch of sewage that it's been saving up--that's why you've got a chemistry spike--it'll settle out soon enough.

The toxicity of NO3 is debatable. If you don't have an algae problem, and everything looks healthy (aside from your chem spike), what's there to worry about?

Ty