I am a novice who needs help with high nitrates

[holley]

I have a 3 month old live sand bottom 75 gal tank, with about 75lbs of live rock. I have been changing 5 gal of water a week since I purchased this tank. I had three anemonies, 3 tangs, two damsels, 20 crabs, 20 snails, 1 starfish, and jaw fish. Now I have 3 anemonies, 2 tangs, 1 damsel, 10 crabs, 1 starfish, and 20 snails.
The filter system is a Fluval 404, with four chambers, two are filled with carbon, and two are filled with a hard donut shaped devices.
The water used to be prefect, but now my nitrates are so high that my fish are dying. This all started about two weeks ago. Since that time I have been changing at least 15 gal of water per week to try and bring the nitrates down. Just this week I start using distilled water after testing my tap water for high nitrates.
I was reading other posting and people were refeering to "cc" and "ro-di", what do the letters stand for, and should I purchase these items?
Do you have any advice for me to lower the nitrates, or am I doing the right thing? If I am doing the right thing then how long should it take to reduce the nitrate levels? I want the best set up that money can buy so please share your knowledge with me and point me in the right dirtections.

 

[beth]

First off get rid of the Fluval as a filtration system! Unless you change the media in canister filters at least weekly, these filters will become nitrate factories, which you can see for yourself with your current problem.
How deep is your sand bed? If you have at least 4", then you could just setup as a DSB [deep sand bed] using your sand and LR as a natural fitration. Add a good skimmer, powerheads and you should see a notable difference with this problem.
cc means crushed coral
ro means water that is filtered by reverse osmoses
ri means distiled water

 

[karvis]

ok... if thw filter thing doesn't work, you can always use ammonia lock & stress zyme

 

[beth]

ammolock and stresszyme is not going to get rid of nitrates. Nitrates are organic byproducts and need to be broken down somehow in the aquarium. Using course, larger grain-sized substrate and filtration media that are allowed to age cause organic materials to remain trapped, producing the nitrates and impeding the completion of the nitrogen cycle in the captive aquarium.

 

[dave flood]

mabe your just over feeding?

 

[pufferfreak]

If you get a wet/dry filter and a protein skimmer that should get rid of your problem. But still do water changes.

 

[puff(er) daddy]

My tank has been running for a year now and I've had high (140ppm) nitrates for about 9 months. I have a wet/dry, skimmer, and every other thing you can name. I've tried macroalgae and tons of other things that haven't worked yet.
It's a process of elimination. What I did was I went back to the beginning and traced my steps and found out what I did wrong. My problems so far was I started out with tap water and a 8 inch aggressive messy eating fish. I also didn't have a clean up crew that matched my bio load.
I can go on for days on the misstakes that I have made, but I'm trying hard to make up for them. It's a long and hard process just stick in there as I am because nitrates are not harmful to fish. Like I said I had a 8 inch Mappa Puffer in my tank for a year with high nitrats and no problems. Good luck and if you find something that works please post it so I can bring my nitrates down as well.