Dead Goby = high nitrates?

[lespaul339]

I have a 150 gallon display with 50 gallon sump. I have 130 lbs of live rock combined in my display and sump.

Stock list:
Yellow Tang
Blue Regal Tang
Copperband Butterfly
2- Ocellaris Clowns
McCocksers Wrasse
Royal Gramma
Banggai Cardinal
Pajama Cardinal
Blue Green Chromis
Lawn Mower Blenny
Purple Firefish


I tested my nitrates five days ago and they were high. 40 ppm. I normally do a 30 gallon water change every two weeks, but had waited about 3 weeks this time around because I started dosing my tank and wanted to monitor my levels to see what my tank uses.

Anyways, after I tested my nitrates and found them at 40 ppm I did a 30 gallon water change. Waited 3 days and did another 30 gallon water change to try and drop my nitrate levels down. Tested my water the next day after the second water change and my nitrates were up to 80 ppm!

Last night I ended up finding a dead yellow watchman goby that I hadn't seen in about a week. And it looked like he had been in there for close to a week. Could one little dead goby be the culprit and raise my nitrate levels that much in a tank as big as mine?

 

[bertoni]

That rise might be due to the goby, but I'm not sure about that. Each tank has some sort of upper limit on nitrate reduction, and we don't know how close to that limit a tank is running. If that one fish changed the nitrate level by that much, the tank might be close to its maximum feeding level. By way of reference, my tanks never showed an ammonia spike due to a dead organism, but mine were rather lightly stocked and fed.

 

[outssider]

what happened to your clean up crew ?....that goby should have been ate-up in no time...

 

[lespaul339]

what happened to your clean up crew ?....that goby should have been ate-up in no time...

The goby was in my sump. He had been down there for about month. He kept getting sucked up into the overflow so thats where he lived. I'd see him come out of the rocks to eat, but hadn't seen him in about a week. So there was no clean up crew in the sump except for a few snails and some pods.

 

[lespaul339]

That rise might be due to the goby, but I'm not sure about that. Each tank has some sort of upper limit on nitrate reduction, and we don't know how close to that limit a tank is running. If that one fish changed the nitrate level by that much, the tank might be close to its maximum feeding level. By way of reference, my tanks never showed an ammonia spike due to a dead organism, but mine were rather lightly stocked and fed.

Everything is still looking healthy in the tank. All my corals look good and the fish seem to be doing great too. I think the goby could have died from me moving some of the rocks in the sump. I'm hoping the high nitrates were caused from him dying, but I won't know until I keep monitoring the tank to see if the nitrate levels drop with some water changes and hopefully they stay low after that.

I'm going to be keep a very close eye on my nitrates from here on out. I have another batch of 30 gallons mixed and I will do another water change in a few days. I hate to do to many water changes all at once. I will post my results in this thread in a few days.

 

[lespaul339]

So I did another 30 gallon water change on Friday night and tested my Nitrates on Sunday and they were down to 20 ppm. I'm thinking the dead goby had a lot to do with The Nitrate spike. Going to test my Nitrates again in a few days.

 

[bertoni]

Sounds like good progress! If the level keeps dropping, I agree that the goby is likely the source of the nitrate.

 

[Icefire]

What brand of test kit?

 

[lespaul339]

I'm using one of those API saltwater master test kits. I know it's not the best kit. I use Salifert for all my other test kits(CAL, ALK, MAG,) and plan on getting a Salifert Nitrate test it soon.