Nitrates

[andysgirl8800]

Does anyone have recommendations for lowering Nitrates in the system? Mine seem to stay at 20 PPM and I'd like to get that lower.

I have a fuge that doesn't seem to grow anything but dinos, red slime, and GHA. Everytime I put chaeto in there, it dies. I have a CFL 23w (100w equivalient) light over the fuge. Fuge also has a 5" DSB.

My DT has 2 175w MH (3h photo period) and 2 110w VHO (8h photo period).

I have a very low bioload with 1 PBT, 2 ocellaris clowns, 1 railway goby, and 1 dragon goby. Inverts include about 10 red-legged hermits (can't seem to keep more than that alive), 1 black long spine urchin, 2 skunk cleaner shrimp, and 1 peppermint shrimp.

I have about 150lbs live rock and a 2" sand bed in the DT.

I was doing a 20% WC every 3 weeks, but upped that to 30% every 2 weeks. I use RO/DI water only.

Any ideas?

 

[Smitty]

That's a tough one...did you buy your rocks from someone instead of the lfs...they probably had nitrates, which is now leaching into your water...or else, it may be what you're feeding...flakes, pellets, etc.

 

[mng777777]

First I would suggest you try to figure out why you cannot grow chaeto, I doubt it's a lighting issue though it could be. Is the CFL a 6500k daylight bulb? How high do you have the light above the water level? You might consider changing or increasing the light over your fuge. Also, Chaeto prefers some flow, how is your flow through your fuge?
Next, I suggest you increase the frequency of your water changes to weekly, you can lower it to 10 or 15% but do it every week and that should help to bring the nitrates down.
What kind of skimmer are you using? Do you have any other mechanical filters that could be leaching nitrates into the system? What does your feeding schedule look like?

 

[andysgirl8800]

Got all the LR from the LFS. Only feed frozen foods every 3 days and feed lightly. Have removed anything deceased immediately from the tank. Very frustrating.

 

[coolhandgoose]

You're running a scrubber too right? How is that running? Are the lights powerful enough on that? Are you getting growth on the scrubber?

 

[andysgirl8800]

The CFL is a daylight equivalent and sits no higher than 6" above the surface. The chaeto has always been placed in a medium flow area with the water flowing right through it. Within days, it would get chocked up with red slime and HA. I tried rinsing it out regulary in clean SW and turning it over in the sump, but only succeeded in washing out a lot of pods. I have an Octopus skimmer that pulls out good skimmate. It is a stand alone model, so no chance of it seeping back into the water. I have no other filter media such as sponges or filter socks, or pads....nothing that would trap and increase nitrates. I've been doing everything I can to get these nitrates down. I'm very frustrated with the fuge portion of my sump because all it has is nasty stuff in it that kills off anything else I try to put in there.

 

[andysgirl8800]

The scrubber has been disappointing also. Getting plenty of growth....of all brown algae, nothing green like I'm supposed to. Was going to try changing the lighting from CFLs to standard bulbs to see if that helps.

 

[coolhandgoose]

You'll get brown though if you have high nutrients (nitrate, phosphate)

 

[andysgirl8800]

Yeah, but it's been running for 2 months now and doesn't seem to be helping.

 

[coolhandgoose]

I just looked at your screen size on the DIY page and it looks kind of small for a 125 gallon tank. If it's lit from both sides you'd want 12x12 = 144 gal as an approximation. Since you are only lighting from one side you'd need 12x24 roughly.
Also for the lighting of the scrubber you're supposed to have 1 watt per gallon for good filtering so you'd need 5x 23W bulbs not 2. I'd maybe try 2 50watt bulbs and see how that does.

 

[andysgirl8800]

Goose,
I have extremely limited space in my sump, unless I empty out the fuge part of it and don't have room in my stand for a bucket. This was the biggest screen I could get away with. Was thinking of replacing the bulbs with 100w ones.

 

[coolhandgoose]

Wow 100 W CFL's is a lot. I think home depot probably has those in the plant growing section (hopefully in the 2700 - 5000k range). I understand the space limitation it does take up a lot of room. I think increasing the wattage would definately help, as long as it doesn't burn the algae, just my 2c.

 

[andysgirl8800]

*L* Appreciate it Goose. I was going to forget the CFLs and go with regular outdoor bulbs instead, and maybe reduce it to just one light instead of 2

 

[mng777777]

SOunds like you are on to something with the lighting... you can rule out skimmer/filtration and feeding as the problem. I would change your lights as you described, and adjust your water change schedule and see how that goes. Also maybe try going w/o the scrubber for a bit and see if that changes anything.