Vacuuming sand bed

[Jessbo]

I have a 125 gal tank. Been up for about a year now. Problem is, can't get rid my nitrates. Been around 10ppm and even with water changes, no drop. After talking with my LFS, believe my problem arises in my sand bed(2-3"). I have never vacuumed it...ever. Some of the sand is from previous tanks, 3 years old, while some is just 1 year old when I set it up. Either way, I thought you were never supposed to vacuum a dsb, just utilize sand stirrers.

So I have vacuumed it twice, changing 15 gal water each time. Barely a drop in nirates, if at all. Within 24 hours, sand bed surface turns from white to green-brownish(algae). Am I not vacuuming correctly, not found the source of my problem??? Please help!

Tank has 125lbs live rock, Amm-0ppm, Nitri-.05ppm, Cal-350ppm, Alk-7, Sal-1.023, Mag 1220ppm, Phos-0ppm. I use RO/DI water, which tested no nitrates and no phos, salt mix(instant ocean) no nitratesor phos. Only have 3 fish, 4 soft corals, so no real bio-load. Just put som bio-balls into my sump(not sure if such a good idea, recommended by another LFS), to help the problem.

Know my Magnesium is low, been slowly rasing it(was at 1100ppm). Been raising salinity to 1.025 also. Then will bump up cal and alk to proper levels. So again, please help!

 

[wrightme43]

Bio balls probley wont help your nitrate problem. More than likely will add to it.
Do you have a refugium, or any macro algae growing to help with nitrate reduction?

 

[Jessbo]

Had a refugium a little while ago, but became plagued with algae, more so than it should have. So removed it.

Is the only way to remove nitrates through water changes or refugiums?

 

[wrightme43]

No, just two of the easiest ways.
If you blow off the live rock, and remove the detirius from the sand bed, it should go away as well.

 

[Jessbo]

Should I only be vacuuming the top inch or so of the sand, or go all the way to the bottom? I am currently sticking the vacuum near the bottom, letting it sit for a second or two, and then moving.

 

[liveforphysics]

Sounds like to me that you have some underlying problem that caused the fuge failure, and is possibily the root of the whole problem.

What lighting was used in the fuge, what macros were attempted, what sort of substrate are you useing, and how deep is it?

 

[fishcrazee]

I lightly vacuum the top inch or so of my sand bed on a weekly basis. Some people will tell you to never touch the sand others advocate some vacuuming. It seems your alk is a bit high? What do you feed the fish? Do you have a lot of algae? How big was your refugium and what did you have in it? What kind of flow did you have through it? How often and how much water do you change? Maybe you stated that...... I change about 15-20% every week, but I also have a new tank. Have you tried anything like De-nitrate?

 

[Jessbo]

My fuge was just 3-4 gal, had low flow through it. Had just 15 watts lighting it(probably too little). Sand was carribean reef sand I think. Came in 25lb bag at LFS. Was superfine, like fine sugar, had kind of pink color to it. Didn't like it too much. Only had sand a some calurpa in my fuge, which went crazy. Kept clogging drain though.

Most of my sand in my tank came from tampabaysaltwater.com . It is mostly medium grade, with some fine sand that I have mixed in.

Thought I should have my alk between 7-11dKH, preferably 9.

I change about 15 gal every week, so that would be about 12%.

Haven't tried a de-nitrator yet because I want to know why my am getting so much trates, but am certainly thinking about it.

 

[bpiermat]

I am having similar problem...no solution yet...I discussed it in a post I started a week ago

 

[mojoreef]

You dont want to vacuum the sand all the way down. Bacteria that reduce nitrate use nitrate for respire, now nitrate is not their first choice, they perfer to use oxygen, and when they use oxygen they dont use nitrate and thus no nitrate reduction. If you airate the bed by vacuuming you will cause nitrate reduction to stop until that area goes devoid of oxygen and thus the bacteria will turn to nitrate.
using bacteria for filtration is a good concept but it is also a slow and it takes many different pathways. Some folks (me included) feel that stirring and remove any detritus that floats out is a reat way to ease the burden of bioload put upon the bed, it also keeps the top inch (areobic zone) well oxygenated which is very good for the bacteria that reduce ammonia and nitrite.
The best thing to do is to try and find the soure of the nitrate, so do some tests in a variety of areas with in your tank. Test the pore water in the sand bed, around the surface of the rocks, put some of the food you feed in water for a while (1 hour) and then test it, test your salt mix water and so on. This should give a good look at the soures.


Mike

 

[Kimo]

My fuge was just 3-4 gal, had low flow through it. Had just 15 watts lighting it(probably too little). Sand was carribean reef sand I think. Came in 25lb bag at LFS. Was superfine, like fine sugar, had kind of pink color to it. Didn't like it too much. Only had sand a some calurpa in my fuge, which went crazy. Kept clogging drain though.

It sounds like your fuge was doing exactly what it was designed to do - give you a place to grow algae for nutrient export. Since the caulerpa was going crazy, every time you remove it to clean around the drain the nutrients that the algae used to grow are removed from your tank.

I am going to be setting up a fuge myself this weekend (if I get time) and I'm trying to go as big as possible. www.melevsreef.com has some good information about refugium lighting that you might want to check out. I believe Melev posts here as well, so maybe he'll drop in and say a few words about it

Oh, BTW, caulerpa is not the best choice to nutrient export. It has a tendancy to go sexual and release all of its accumulated nutrients in one go. Something more stable like chaetomorpha or gracillaria would be a better choice. Just FYI.

Jamie

 

[Jessbo]

Tested some water between two rocks, put a small crater in sand bed, and got as close as possible to sand to obtain sample also. Both results are higher than 10ppm, but not fully 20ppm. So it seems my rock and sand are the sources of my problem.

So would you suggest taking most of the rock out of the tank so as the stir the sand as mojo suggested then follow with a large water change? What would you recommend about the rock? Do you think I need to bake it(put into rubbermaid with no light, good circulation and heat), or just arrange it differently? Currently, the rock is like well, and pile of rocks in my tank. Have most of it off the sand bed, but more stacked on top of each other, mainly for support and stability.

 

[Jessbo]

Someone suggested to me that since I plan on keeping mostly sps, that my sand bed would be better if it was only .5-1" deep, compared to the 2-3" depth it is now. I would like to have a few softies though, but not sure if that is enough of a reason to keep the sand so deep.

 

[alison]

add some friends

maybe replacing parts of your sand would help a bit, sounds like you have quite a mix in there. You might also drop a few cleaner shrimp in the tank; that would help with picking up food your fish don't eat.

 

[liveforphysics]

I dont wana beat this into the ground, but perhaps if you got some proper lighting (its really cheap) and some chaeto in your fuge growing rapidly that you would notice your problem dissapears. Once again though, if you dont give it the conditions to grow rapidly, its not doing anything bennificial.

I find its an exellent nitrate and phosphate export. If you want some, I PM me, but get the lights first or you are wasteing your time.

 

[alison]

Would a UV sterilizer do any good?

 

[houmamctc]

My nitrates stay @ +/- 10ppm constantly with no growth problems whatsoever. The biggest thing I have found to control nitrates is a fuge. My 100 gallon uses a 35 gallon fuge with a flow of 125 gph. Excellent calerupa growth. I have to trim it back every month. This also causes a temp nitrate spike.

 

[fishcrazee]

[QUOTE=J

Thought I should have my alk between 7-11dKH, preferably 9.


I was thinking you were talking 7 meq/L not dKH. Alkalinity should be between 8-12 dKH, from what I've read.

 

[Jessbo]

To my knowledge a UV sterilizer won't due anything for the nitrates, just ease the problem it is creating.

Just emptied most of the water in my tank, removed all the rock, and found soooo much detrious!!! Stirred the top inch of sand and then vacummed it up. I am re-arranging the rock to more pillar like formations, with very little touching the sand bed, lots of flow through and around.

Probably will more than likely incorperate a fug here pretty soon. How many watts per gallon should I shoot for in my fuge? Will try some chaeto instead of calurpa. I never liked the calurpa anyway, think it had some negative effects on my tank.

 

[liveforphysics]

Well, its not the watts per gallon, its the amount of light that hits the surface of the water with-in the angle limit of salt waters critical angle, and then beyond that, for that remaining amount that hits the water, its the few bits that actaully strike the parts of the algae that can do something with photons.

What im getting at, is you could have a 500watt halogen flood lamp over your fuge with a crude reflector and be providing less useful light energy than a single 23watt florecent spiral reflected spotlight bulb.

Also, you could be pumping in a ton of the wrong wavelegnths of light (like I did with the 10k and the 6.5k setups) and also not get any useful growth rates.

I struggled with quite a few differnt arangements until i stumbled upon this 4 pack of intigrated reflector compact florecent spotlights that home depot sells. They grow algae better than anything else I have ever used, and the algae is very stable, dark, and structurally stronger now.

I dont have a pic of the packageing, just of the bulbs themselves, so if one of the many people who have told me they switched to this bulb and loved the results would post a pic up of the packageing, it would be a nice thing to do.