high nitrates tried everything

Question
I have a 40 gallon Eclipse saltwater tank. The rock is from two previous smaller tanks as I upgraded every few yrs, and is about 12 yrs old. I have live sand about 1.5 inches deep. The nitrates were always a problem the last few years despite water changes (and I do not feed the fish alot). Recently the powerbar everything was plugged into failed and I lost my three fish.
Since the nitrates were high (off the scales over 100 easily) I decided to start all over.
I emtied out the live rock, then siphoned out the tank water into the container, immersing the live rock to prevent die-off. I emtied the tank, took out 85% of the sand thinking it was just to dirty and probably causing the nitrates.  I put in new fresh packaged sand and mixed up the sand. I then filled the tank with new RO saltwater (tested 0 for nitrates), put in the old rock, and topped off the tank with about 4gallons of old water. The nitrates were then tested at 20.
I bought a cleanup crew, snails and crabs and a nudibranch. No fish.
One week later the nitrates have climbed up to 70 already.
Could it be the rock? and what should I do?
Can you take it out and clean it somehow? Bleach?
I really could use help, I want to have a nice reef tank.
Thank You,
Rebecca Kalakota
(would love to speak to you)

Answer
Hi Rebecca,

Nice to meet you.

From your description, it sounds like you are doing everything correctly.

Cured / Seeded live rock will never pose a threat in regards to causing high nitrate levels. Cured live rock generally will never need a good cleaning unless it gets overgrown with a species of nuisance algae, like hair algae.

Here are a few tips below, to help keep your nitrate levels lowered in your nano aquarium:

Firstly, you want to make sure the nitrate test kit that you are using is accurate. Some universal nitrate test strips can be inaccurate, and nitrate test kits that are not used very often can expire and give a false reading. You want to be certain that the method you are using to test for nitrates is as accurate as possible. Investing in a quality nitrate test kit is often worth the extra money.

I'd recommend to incorporate a protein skimmer, if you don't already have one; this will definitely help to keep doc levels to a minimum, by directly removing dissolved organic compounds and other raw waste before it has a chance to breakdown further into nitrates.

Occasionally, I'd say a couple times a month, you should introduce / dose your aquarium with a beneficial bacteria. This will help to keep your aquarium biological processes in balance; because ultimately it's the good beneficial bacteria that breaks all waste down, to keep the aquarium from having deadly ammonia and nitrite levels. These good beneficial bacteria are naturally present in the wild, but in the home aquarium there is almost none, unless introduced.

A couple good beneficial bacteria for marine aquariums include BioZyme and Brightwell Aquatics MicroBacter7, these can be found at your local fish store and they're also readily available from quality online retailers. See the web pages below as an example:

http://www.ocreef.com/brightwell_aquatics_microbacter7

http://www.petco.com/product/5626/Aquarium-Products-Saltwater-Biozyme.aspx

You could introduce a beneficial species of macro-algae like Red Grape Algae or Chaeto, these will help by absorbing nitrates from the water, because these algae use them as a food source. See the link below as an example:

http://www.ocreef.com/rare_red_grape_macro_algae_live_coral_refugium

I'd recommend to feed your fish a variety of high quality fish foods; you want to use fish foods that are more natural and have less artificial additives, that won't contribute to the rising of nitrate levels as much.

Lastly you should be using a quality reef-safe carbon media in your water filter area. Your Eclipse filter will recommend to use their filter cartridges, which is fine, provided they are using high quality high grade reef safe carbon in them. Perhaps instead of always using the Eclipse filter cartridges, you could use a media bag with your choice media, inside your filter chamber; it should work very well, as long as water is able to pass freely through it. In conclusion this will allow you to incorporate quality media inside your water filter area, which ultimately will result in cleaner and healthier water for your aquarium inhabitants.

A good media that I personally use in my filters and that is readily available is Seachem SeaGel, it's a mix of high quality carbon and phosguard (phosphate removal media), see the link below as an example:

http://www.ocreef.com/seachem_seagel_250_ml

I wish you luck with all your current and future saltwater aquarium endeavors.

PS: In the future, let me know if you were able to get your nitrate level down, and how you eventually accomplished doing it.

Sincerely,
David - All Experts