nitrates driving me crazy

I have had my 55 gallon tank for about 4 months now. I purchased it on Craigslist. It came with everything including fish. When i first moved it i used the old sand and my nitrates were very high. Between 80-100. I replaced the sand and most of the water and it dropped to 20. It has hovered there for the entire time with no ill effects I could see on fish or corals.

Recently it went to about 40-50 and some of my corals are not opening all the way. My understanding is that nitrates are like credit card debt...no time to get in truoble but a long time to get out. I have been doing 5-6 gallon water changes every day for a week and have cut back on feeding. Yet the nitrates will not go below 40. I am thinking that I will do a twenty gallon change but am worried about the massive change be bad for the inhabitants.

Other test are great o amminia, 0 nitrites calcium at 450 phospates 0 ph at 8.3 temp is a constant 76-77. i have a chiller and a heater working in the sump. The heater is controlled by the chiller. I have removed the bio balls and clean the mechanical filters every other day.

My 34 tank that has been neglected and has very little rock and 2 damsels is perfect. I use RO water to mix my salt (I use red sea coral pro salt) and one tank is perfect and one is driving my nuts. Am I missing something? Should i do something else? Do i need to do a big massive water change? Any help would be appreciated.

Thanks for looking and any help.

 

You need to find whats causing your No3 issue. I know, its easier said then done.
1. Do you have enough LR?
2. Do you have a sump or a refugium?




luna

 

I have been having similar issues. I can't seem to get mine down, either. Water change and they build right back up even with a good skimmer.

Maybe something is leeching out of your rock? I got my rock from a few stores in Tampa and I noticed that the Marco rocks I got has covered in coralline in just a couple months. The rock I got down there and transferred to my 75 barely has any after over a year. Bad juju I think.

Good luck and keep us posted on your problem.

 

I was in the same boat as you with 20ppm for the longest and never dropped even after a 25g WC. After I installed the new sump/refug, it went to zero and has stayed there ever since.


luna

 

this might help

Melevsreef.com | Acrylic Sumps & Refugiums

and from Powerman
http://www.3reef.com/forums/reef-aquarium-articles-how-tos/all-about-sumps-filters-fuges-79852.html

 

When my tank was about 3 months old I was having horrible nitrate issues and I couldn't get them to go down. I added some SeaChem Purigen filter media and was very diligent about weekly water changes and they eventually went down. It took about 3 weeks for the Purigen to work. Now the nitrate levels are just fine and I have no algae problems.