Ok im stumped on my nitrates

dedubya · Aug 23, 2012

Ok 1st off the tank im referring to is a 120 gal with 39 gal sump only holding equipment in sump, and 30 gal fuge with dsb/chaeto, about 100 lbs of LR in the tank,5k gph flow,filter sock,biopellet reactor, carbon reactor, and ASM G2 skimmer.
Livestock is 6 fish 2 cinnamon clowns,yellow tang,coral beauty angel,baghai cardinal,and a dragonet. I cannot get my nitrates below the 15-25 mark, I only feed small amounts of food every other day, and add a strip of algae for tang/angel 2 xs a week. 20 gal water change weekly.
The nitrates are driving me insane so about 4 months ago I added the biopellet reactor, and yet it has not changed the nitrates, they have tons of tumbling going on. Im also getting small amounts of algae on my frag rack that is inside the tank but nowhere else, it's black egg crate. Lighting is an 8 bulb tek 5 system,I run for 8 hours total daily. I dont want to starve my fish and even feeding them every other day, everytime I walk by the tank they are like dogs and come rushing to the corner that I feed in hopes that I feed them, so I kind of feel like im underfeeding. I do not run a reactor for rowa phos since I have the biopellets. My ro/di tds is 0 and to verify it I did a nitrate test on the fresh water and reading is 0. with salifert test kit that is about 3 months old. My phosphate test also salifert reads 0. Any advice on what to try next? Although my coral seem to be fine and happy I would like to get my nitrates down.
Think the asm g2 is really underpowered for this system? If so what would be a good 1, and why have the biopellets not worked the way they should? Any advice would be much appreciated, and thanks in advance.

beaslbob · Aug 23, 2012

Nitrates are hard to get down but with that said 15-25 ir not really all that high. I know I know high for some corals but it could be a lot higher and would be if you for what you are doing.

To me the key is increasing the nitrate consumers. So I used macro algaes and got unmeasureable nitrates and phosphates.

Als one thing to consider especially an newer tanks is that as aerobic bacteria is building up, macro algaes will consume ammonia instead of nitrates. So it is possible even expected you get a small nitrate bump during that time. Then as the bacteria consume more and more of the ammonia nitrates finally drop down.

If you are beyond that stage then I would recommend more macro algaes.

And just for fair warning when the nitrates do drop I tended to get cyano. All the sudden and in only a few days it covered everything. So what I do at that point is kill the lights and stop feeding until the cyano dies off. Then resume with lesser light and feeding to keep the tank in balance.

my .02

Degener8 · Aug 23, 2012

Are u running enough pellets in the reactor? Also even though u feed sparingly how much of it is unconsumed. You may be better off to feed less at one time but feed daily.

46gReef · Aug 23, 2012

In my experience the best thing to do to reduce nitrates is a series of large water changes(for a system your size I'd say 40 gal.) every 3-4 days until your levels start to go down...what is your substrate in your DT? Have they always been at 15-25 or did they start lower & slowly creep up?It definately doesn't sound like your overfeeding so maybe it's just a snowball effect where they started low, crept up & now your 20gal weekly changes aren't enough to get them down, their only enough to keep them from going up....just a thought

46gReef · Aug 23, 2012

Also, maybe try caulerpa in your sump instead of chaeto, grows 10x faster & therefore exports nutrients much faster, I would disagree that 15-25 isn't high, way too high IMO for a reef tank....

Downbeach · Aug 23, 2012

Your pellets should be tumbling, but very slowly, just enough to keep them from clumping, kind of like running GFO. I would get a GFO reactor, and use a Hanna checker for PO4. Have you tried adding any bacteria, i.e. Biodigest, MB7, etc.? Have you tried checking your make up water? You could be adding it every time you do a WC.

Kkaz642 · Aug 23, 2012

how often do you do a water change? also how many power heads/whats the rockwork look like you can increase your water changes( no one likes to do) lol, try increasing your flow and get rid of the dead spots in your tank behind the rock, buy a nice cleaning crew they will eat that extra food espically if you have a sand bed add some to your sump also. sometimes the simplest solutions work best! good luck

Kkaz642 · Aug 23, 2012

also i feed my tank every other day and they are fine. with the algie strip make sure you dont leave it in ther too long once most of its gone pull it out before it decays.

dedubya · Aug 23, 2012

it's a barebottom tank so no substrate, age this month makes it a year old so it;s past the ne tank stages. Also my biopellets are tumbling super fast I actually have about 900 ml of pellets in the reactor since I read you cannot overdose with them, and a mag 5 tumbling them. I do leave the algae strip in overnight at times that may be bad.Large cleanup crew of snails/crabs.The tank is a 48x48x12 so the rockwork is spread enough that there are no dead spots.

Downbeach · Aug 23, 2012

The flow regimes within the reactor have a direct correlation to the effectiveness of biodegradable polymers in terms of nutrient reduction, so I would reduce the flow in your BP reactor so the pellets are just gently tumbling along the top. You might also add a good bacteria, like Prodibio's Biodigest or MB7 to get them going. It should also be kept in the dark. Give this a try and check your NO3 and PO4 in about 3 weeks. If you need to get your PO4 down to low levels, you will probably have to start using a GFO reactor.