Clean out my sand, or no?

3 months ago I bought a 75.  I tested nitrates last week and they were off the charts.  Ammonia and nitrite read 0.  I also had a gorgeous carpet of ruby red cyanobacteria.  I bought the tank used, and when I transported it I very much disturbed the sandbed without cleaning it.

I was going to say your Cyano could have dissipated because of the lack of food (nitrates and the likes thereof). have you list any livestock? Do some big water changes that's for sure how deep is your sand bed and how much rock do you have?

I have a huge foxface rabbit, a file fish, a yellow tang, and a pair of clowns.

I don't have enough rock, that's why I'm getting more. I'd say it's around 40 lbs, give or take. The sand bed is 3 inches.

Nikki, I like your advice because it means less work (HA!) but how many people are "sooooo many people"?  Just as a matter of curiosity, of course.  :)

And when you mean taking cores, are you suggesting getting all the way down to the bottom?  I'd read that you didn't want to disturb those anoxic zones.

Yes I have been using tap water.  No more by the end of this week.  I feed two pinches of flakes every other day and I've been putting up bits of nori up until the last few days when I ran out.  Getting more of that today.

I agree w/ Nikki.

Good info.

Crappy cheapo flake food from Petsmart.  Any recommendations on food that's available at Petsmart?  Or over the internet?

Aloha Chris,

It hasn't been mentioned yet but a Nitrate level of 40 ppm is not way off the charts. Though below 10 ppm is much preferred, many perfectly good tanks have temporary levels of up to 80 ppm.

Careful - Cyano sometimes disappears in the morning but comes back later in the day.
The reason why the Cyano would disappear and not return is because 1) the bacteria population in the tank has grown and is catching up to providing sufficient biofiltration and/or 2) the nutrients being dumped into the tank via food and tap water have decreased. That's the story of the rise and fall of Cyanobacteria.

I wouldn't be surprised to hear that the Nitrate level is already decreasing. Have you tested it since last week

How much Macroalgae is still in the tank? Have you allowed the small bunches you added early on to remain and grow? Well illuminated Macroalgae makes a huge difference as it eats up "ANPN" pollution (Ammonia, Nitrite, Phosphate & Nitrate). The Macroalgae I added to my 40 gal tank almost 4 weeks ago has doubled in size. It would now almost fill a five gal bucket. The tank is now to the point where the Macro can be cut back. Ready to share with other hobbyists in need.
[edit] just realized something - 2 major herbivorous fish means no more macroalgae in the display. What about a Refugium

I wholeheartedly agree with Nikki and Bob. Simply vacuum the substrate.
Though I personally wouldn't worry so much about an aggressive schedule, just vacuum a part of the sand at each 10% monthly water change. I will add double value to Nikki's number of hobbyists I've known over 10 years on this forum that have severely damaged the biofiltration and crashed their tanks by the action you were first considering.

I may be traveling to Logan this evening to pick up some lights. I could stop by and check on your tank if you like. Call/text me.

Mahalo,
Mark
808-345-1049 anytime


Edited by Mark Peterson - June 10 2013 at 10:16am

@Mark - It was well over 40 ppm the last time I tested 2 weeks ago. I want to say my kit goes up to 100 ppm and the test sample was easily darker than that the indicator for that.

I have plenty of chaeto growing in the sump.  It hasn't grown to fill a 5 gallon bucket yet, but I've noticed that the clump has gotten bigger.

I don't think I'd have too much time for a visit tonight, I'm so sorry. 

@Ann - I can't tell what you're saying, are you saying to clean out the sand? 

chris.rogers wrote: @Ann - I can't tell what you're saying, are you saying to clean out the sand?

The wink meant I was kidding.  I fully understood, Ann.  :)