High Nitrates - FOWLR

[SHARPiE]

Hi All,

I've been struggling for the past month or more with high nitrates -
Here is my system:
42G Hood Tank (no sump) - FOWLR - Wet dry trickle filter, Protein Skimmer, small amount of macro algae, 36 pounds of live rock. 2 Blue Green Chromis, 2 Clowns, 2 Kaudern's Cardinals, coral banded shrimp, sea star, stromb snail and plenty of hermit crabs. 5 stage RODI system for PWC's.

Parameters:
Ammonia - 0
Nitrite - 0
Nitrate - 40
SG - 1.025
Calcium - 400
Phosphate - 0
pH - 8.2
Temp - fluctuates between 25 (77F) and 28 (82F) on hot days
Lighting - standard 3 fluro hood setup on timer for 5 hours a day

I have been doing weekly 10% water changes, but have been doing water changes twice a week since I noticed the high nitrates.

I have cut down to every-other day feedings, in an attempt to reduce waste. One day thawed, rinsed, enriched brine. The other day is tiny marine pellets. I feed a relatively small amount - all food is gone within 1.5 mins.

The macro algae has been taking off, but not helping with nitrate reduction. I also had high silicate and phosphate readings a couple of weeks ago, and have used phos-zorb to reduce these. Since then my coralline algae has taken off!

From what I have read, PWC's is the way to reduce nitrates, but I am not noticing any reduction - its sitting steadily at 40ppm. I use RODI water, and it has zero nitrates when I add it to the tank.

Any other ideas??

Thanks
​

 

[eatsomepopcorn]

Have you tested your equipment to ensure that you are not getting a false read? Have you tested you water coming out of RO/DI to ensure you get a zero read on that? Do you regularly vacuum your sand and do you have enought waterflow within the tank, I run a 44g pentagon and run two powerheads and a fluval 305 and keep nirates at 10ppm with only 10 lbs of live rock and no protein skimmer. I had a bad test kit that kept reading high on nitrates, bought a aquipure denitrator and later discovered my nitrates were zero, it was just the liquid test kit that was bad. I went to a powder kit and the nitrates went to zero. I never had a problem to begin with.

 

[SHARPiE]

- I have tested the RODI saltwater mix before I perform the PWC - 0 Nitrates. So I am fairly sure the test kit is OK - its a liquid API test kit. I might pick another one up to ensure this isn't giving false readings.

- I think water flow could be an issue - so I'll invest in a powerhead.

** Edit - Vaccum with each PWC

Once I have installed these and let them run for a while, I'll give an update

 

[eatsomepopcorn]

Sounds like a plan. Certainly you could step up the water changes to 25% if you want to see if you can get down to 10% or near zero and then see how quickly you rise. Also, 40ppm is not the absolute end of the world, but you always have to ask yourself if your tank is over stocked as well. A small tank such as yours has limits that may take more drastic measures to correct such as more rock, bigger sump, denitrator.

 

[saywill]

What do you have for a base? Crushed coral or sand??

 

[mfdrookie516]

Wet dry trickle filter

almost bet this is what's causing it... are you using bio-balls or lr rubble?

 

[SHARPiE]

What do you have for a base? Crushed coral or sand??

Crushed coral - about the size of raw sugar grains

are you using bio-balls or lr rubble?

Neither - using cermaic noodles under a thin black foam and some white filter floss.


Update - I went in to the LFS, and they said that the waterflow would not be an issue... He advised against a power head, might have to buy one on eBay- He then tried to sell me another $350 skimmer . I didn't want a bar of it, so he eventually showed me a product that removes nitrates and algae causing nutrients (litte white pouches that you put in your filter). I'll give it a week or so and let you know how my nitrates are doing.

Also - got another nitrate test kit - same reading.

I might order a power head over the net - as they were trying to charge me $70+ for a small powerhead.

 

[cmor1701d]

I've heard of people with a wet/dry havig low nitrates. I've heard of people with crushed coral having low nitrates. Having both jsut sounds like nitrate trouble. Now a reading of 40 for a FOWLR is not terrible. If you want to lower it it you need to vacuum the gravel and do more pwc's.

 

[saywill]

I had lots of trouble with crushed coral and high nitrates, after replacing it with sand, the issue was over.

 

[Floyd R Turbo]

...a product that removes nitrates and algae causing nutrients (litte white pouches that you put in your filter)

Was that Seachem Purigen? Good product. It removes dissolved organics, it doesn't really remove Nitrates themselves, rather the products that result in them. I run them in all the tanks I maintain and keep myself.

Crushed coral, from what I've been told, can trap detritus and cause Nitrate problems, but if it's fine enough like you said 'size of grains of sand' you might not have that problem. Cutting down on food should help. Adding more LR might help too - how much do you have? Is your skimmer producing enough skimmate? It might need a good cleaning or adjustment.

 

[SHARPiE]

Thanks Floyd

...a product that removes nitrates and algae causing nutrients (litte white pouches that you put in your filter)

Was that Seachem Purigen?

The product I have is called Algone: Algone.com - The Aquarium Water Clarifier & Nitrate Remover
It says it Absorbs Nitrate, Starves Algae, Clears Water, Reduces Water Changes and Tank Cleaning, Increases Dissolved Oxygen - For Fresh and Salt Water. Natural fibre mix, Bio is safe, natural aerobic waste-dissolving microbes.

Crushed coral, from what I've been told, can trap detritus and cause Nitrate problems, but if it's fine enough like you said 'size of grains of sand' you might not have that problem.

Every water change, I dig around with the vaccum and pull waste until the water coming out is clear.

Cutting down on food should help. Adding more LR might help too - how much do you have? Is your skimmer producing enough skimmate? It might need a good cleaning or adjustment.

I have around 40 pounds of live rock.
The skimmer produces a full cup of black/green sludge every two weeks.

Will wait until my next PWC and will give Nitrate readings.


Cheers again for all your input!

 

[thincat]

I have my doubts that "algone" removes nitrates. It handles the problems that causes nitrates but a good PWC is more then likely the factor that reduces your nitrates.IMO