Nitrates

[plomanto]

I am out of ideas so I am asking for a little help.
About a month ago things in my 120 started not looking so good, so testing the water i found nitrates to be high around 50. I did a large water change I also pulled all the rock out (thinking something might have died) I found nothing all creatures were acounted for. In the past two weeks I have been doing 20g water changes 3 or 4 days apart. I have cut feeding down to only a small ammount of mysis shrimp daily.
I did another water change Friday (20g) Nitrates are still at 50
All other tests look good
Temp = 80
Salinity = 35
Amonia = <.25 ( test water is totaly clear)
Nitrites = 0.0
Nitrates = 50
Phospates = 0.0
Alk. = 9.9
Calcium = 440

Lighting - 2 x 250 10k mh and 2 x 96w atinic pc

Flow- Mag18 for return, 2 x sieo 820, 1100 GHP closed loop blow ing from behind my rocks.

A Large DIY becket skimmer using a Mag24

29g sump with about 12g used as fuge with sand and chateo.

I have moved some of my LPS from my 120 to my prop tank and by the next day they are fully open and looking great. Fish and clams look fine.

Some one mentioned that my sand bed may be dieing, I dont know

So if I am missing something or you can think of any thing I can do , please let me know

Peter

 

[DJ88©]

[moved]

 

[hopper]

Your salinity reading. Hope thats wrong. 1.025 is where I keep mine.
Have you had someone else do a nitrate test for you (LFS). Could be the test kit. I had a similar problem when I first got my tank started and it took awhile, but eventually the nitrates came down.

 

[hopper]

Ammonia levels should be at 0. You shouldn't even be showing a trace IMO. Ammonia does lead to nitrates.

 

[ojreef]

Salinity reading

Salinity reading

FWIW, salinity readings are measured using two different readings
much like, temperature is measured as degrees in far. or centigrade. One method is called salinity and the other is called Specific Gravity.

A SALINITY reading of 35 is approx. equal to a SPECIFIC GRAVITY reading of 1.027.

I bet if you check whatever you are using to measure your salinity will have both scales listed next to each other.

 

[hopper]

Didn't think about the two different readings. I have just always gone by the SG.

 

[plomanto]

I use the 35PPT reading its just easier for me to see..
The lowest reading on the sailfert amonia kit is <.25 whick the water in the test vial is clear.
I use the nitarte test on my prop tang and get a reading of 0... So i would think it is good

 

[plomanto]

Bump

 

[Craig Lambert]

This is a tough one plomanto. A fuge and good skimming are the best way to reduce nitrates. Water changes are often just a band-aid, as nitrates can retun to their previous level. How heavily is your tank stocked, and what was your feeding regiment before you cut back?

It's hard to comment on a DIY skimmer. Do you feel that it is adaquate for a 120G tank? How long has the tank been up? I'm wondering what the age of your sandbed is.

 

[plomanto]

My tank is a little heavy on fish. The Water has been good up to now.
Yellow Tang, Purple Tang, Pair Tomato Clowns,Bluethroat Trigger, Fairy Wrass, Lawn Mower Bleny

The DIY skimmer was run on a 265 for well over a year befor the guy I got it from got a bigger Tank. I think it is more than enough for my 120.

My tank has been up for 16 months sand bed is the same age.

As far as feeding I was feeding Formula two flakes in the AM and Mysis shrimp or plankton in the PM...

Now I am only feeding a small amount of well rinsed PE Mysis shrimp

 

[Cord]

As far as your sand bed dying, How deep is your sand bed? Is it a coarse sand size which detritus could work down deep between the sand grains? I use 3 inches of sugar fine arag in my tank and have never bumped over 0.0ppm. Do you stir up the sand? This could disrupt the denitrifying bacteria in the DSB, and release nutrients.