Nitrate and Phosphate Question

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Domboski

Dwarf Caimen
Joined
Feb 12, 2006
Messages
54
Location
New York
I hate to do this but I have read and read and read some more about Nitrate and Phosphate problems and I can not get a handle on my situation. I have a 20 gallon hex with a protein skimmer, UV light, Refugium, Seastorm, Fluval 404 and Fluval 104, sand, 10 or so lbs of live rock, SPS, Yellow tang, percula clown, coral beauty, white wrasse, Long tentacle anemone, 4 fighting conches, 2 peppermint shrimp, 2 cleaner shrimp, chocolate chip star, 2 camel shrimp and one fire shrimp. the tank has been running beautifully for over 6 months! I used to have more fish in it believe it or not and it was much better as far as water quality. It has been two months since I removed a lot of fish and now I can not get the nitrates or phosphates down. 50% water changes weekly, PH 8.2, Temp 78-80 F, Ammonia 0, Nitrite 0, Nitrate off chart, Phosphate 3PPM, Calcium and alk are perfect. I also have a 150 coralife MH.

I always use RO/DI water for changes.

Please help! I even have a great stock of pods living in the tank too.
 
Ahh man...Know the feeling. I see you are using fluval cannisters. What do you run in them and how long before you change media, sponges etc? Also, are you running a dsb, and 10lbs of LR is not all that much rock to perform that much denitrification in a tank that size with that much bio-load IMO. You usually hear 1-2lbs of LR per gallon. What do you keep in your refugium and what size is it? Also, what test kits are you using and how old are they? Sorry so many questions, but I'm sure they would have popped up anyway to help figure out where the problem is coming from. Hopefully we can get you sorted out:)
 
The refugium is about 2.5 gallons full of chaeto and about an inch of arogonate. I have bio balls, carbon, phosguard, and polyfiber in the canisters. I use salifert test kits. I have not changed the carbon in quite some time. I usually only rinse it out in clean salt water. The carbon socks have so many pods in them I hate to get rid of them.

I always test the ro/di water and the water again after I add salt and it always reads 0.
 
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Do you test before and after the water change? If you get a drop how long does it take for the nitrates to increase?
 
That's just it. Sometimes it drops and usually it doesn't. I can't imagine that my bio filtration is not enough. I had way too many fish in this tank before with the same filtration and everything was zero. It is a mystery to me. Only once in the past few weeks did the nitrates and phosphates decline after a water change so three days later i did another water change and then the next day, off the charts again.

Do you think it is the sand bed (I doubt it because the sand is constantly disturbed by the clown fish and me)? Should I completely change the carbon and sponges?
 
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Now, when you say its "full of chaeto", the quanity of chaeto is irrelivant, what matters is the growth rate.

Ron Schemicks article about chaeto recorded it increaseing its mass by 5.5 times in a week!!!! I personally only think mine about doubles, or maybe tripples each week, but reguardless, just having chaeto does nothing.

The export occurs when chaeto converts the N and P into more chaeto, which only happens during growth of course.

My personal best advise would be to get some strong bulbs of the right type over the fuge, and get get some good flow through it. I use my fuges as sumps, so its a constant waterfall in right onto the chaeto from the overflows, and a big pump blasting it back into the tank. In my personal experience, and I know this is differnt for most people, but I have never got a fuge that had slow flow to look healthy, or rapidly grow chaeto.

I hope that helps you!
-Luke
 
That helps. I find it interesting. I use the Fluval 104 as the pump for the fuge that over flows back into the tank. I don't think my chaeto is growing at all. I use the Home Depot 23 watt compact flourescent spiral. I have another fuge on another tank that uses a coralife compact F meant for a fuge and the chaeto does not seem to grow there either. The algae does though.
 
What kind of things do you have that would increase nitrate? examples: bio balls, foam pads, filter socks, basically anything spongy. It would help a lot to try to remove all of this from your system. You have a pretty heavy bio load for that size tank but that doesn't mean it won't work. What is the kelvin rating for your refugium lights? that can make a big difference. Also, out of curiosity, what kind of skimmer do you have?

Tim
 
I have bio balls, carbon, phosguard, and polyfiber in the canisters. I use salifert test kits. I have not changed the carbon in quite some time. I usually only rinse it out in clean salt water. The carbon socks have so many pods in them I hate to get rid of them.

This may be part of your problem here...Carbon can't be washed and reused. Once exhausted, it is of no use and has to be changed before it leaches back everything into your system.

Also, you may not have noticed any high nitrates etc in the beginning because the tank was still young. Nitrates don't just come over night and they build up over time when not exported. As for the bio-balls, they will provide surface area for biological filtration, but nothing for denitrification. That's the crappy thing about bio-balls (cannot de-nitrify). LR is much better as denitrification can take place within the rock. About sponges, I don't use any at all in my system because if not washed out regularily, will act as a biological filter like the bioballs and have no way to perform denitrification. Sponges are great if you allow them to just trap junk and then remove them by rinsing or changing them, but if you leave them in too long, the crap will just rott and degrade water quality...
 
Just another thought, I used to have only a fluval running my 55 and I went through this same battle. I took out all the fiber pads in the canister and ran carbon in one chamber (replaced monthly), phosgaurd in two chambers (until my phosphates came down, then just one), and left the 4th empty. It took lots of water changes, and at least a month to fix everything. I just thought I would throw this out to let you know that many of us have gone through the same thing and at times I wanted to throw my tank out the window. Just keep trying and we will do our best to help.

Tim
 
krish75 said:
This may be part of your problem here...Carbon can't be washed and reused. Once exhausted, it is of no use and has to be changed before it leaches back everything into your system.

Also, you may not have noticed any high nitrates etc in the beginning because the tank was still young. Nitrates don't just come over night and they build up over time when not exported. As for the bio-balls, they will provide surface area for biological filtration, but nothing for denitrification. That's the crappy thing about bio-balls (cannot de-nitrify). LR is much better as denitrification can take place within the rock. About sponges, I don't use any at all in my system because if not washed out regularily, will act as a biological filter like the bioballs and have no way to perform denitrification. Sponges are great if you allow them to just trap junk and then remove them by rinsing or changing them, but if you leave them in too long, the crap will just rott and degrade water quality...

I believe Krish has hit the nail on the head for you! When I had a 75 gallon tank, with the built-in trickle filter in the back... It also had the Bio-Balls in it. At first, my tank ran very smoothly... then about 3-4 months into it, the Nitrate levels began creaping up to the point I was pulling out my hair. I was told to remove about 1/4 of my Bio-Balls a week, until they were completely removed. I was a little leary, but followed the directions that other's had given me here... testing about twice a week during that month, afraid I would soon see a spike in Ammonia, Nitrite, or a even worse spike in my Nitrate. Nothing changed in those levels in that month. About 2 weeks after fully removing the bio-balls... I found my Nitrates had dropped to less than 5 on their own! Within about another month, they were undetectable. Yes, I had converted that bio-ball chamber to a Fuge at that time as well... so I'm sure that my Chato helped with that finall drop... but just removing the bio-balls did wonders for me.
 
Thanks everyone. I will remove the bio balls slowly and remove the sponges. I will also replace the carbon. I am not sure what the kelvin is on the bulb. I have seen many people recommend those spirals for fuges so I thought I would give it a try.
 
What you are experiancing is the difficulty in running a nano tank.

Everything said about the nitrate earlier is true. I would just add that your never going to get rid of it. You don't have any nitrate reducing system. No DSB, not enough live rock, the only hope is that your cheato is sufficient.

About the phosphate. The only source of phosphate is fish food and fish poop since your using RO water. Since you have a bioload with those type and that many fish that would tax a 50 gallon system crammed into a 20 gallon system you are going to continue to see high phosphate and nitrate numbers.

Wish the news was better.

Mike
 
what is dsb?

Deep sand bed. Alot of people use them because in the lower region of them, if setup properly and maintained properly, will help in denitrification. There are pros and cons to dsb (deep sand beds) ssb (shallow sand beds) and BB (bare bottom) I am a bb fan and have been enjoying it since I went that route:)
 
until you get your nitrates under control you need to get rid of any filter you are not willing to change or clean every other day. this includes the bags of any absorbant (carbon, phosban, etc.). the key here is to clean whatever filters you have every other day for 2 weeks or more and do regular water changes after blowing everything off the rocks and cleaning the walls and siphon the sand. dont go too deep on the sand if you clean the whole surface, maybe half the depth of the sand for now. you can keep all the carbon and other stuff as long as you clean the bag every other day and ditch the bioballs- especially in a canister filter! for people with this problem i recommend reducing your mechanical filtration to 1 or 2 easy to clean / change items to make sure the cleaning gets done! also MANY foods and additives contribute to the problem. test makeup water one step at a time after each item you normaly use is added and this will tell you if anything you use is importing extra N or P. ive had brand new bottles of " reef additives" test off the charts! test everything! it will save you a lot of grief in the future!. hope this helps. good luck and have fun! this should be fun even when there is work involved!
 
for people with this problem i recommend reducing your mechanical filtration to 1 or 2 easy to clean / change items to make sure the cleaning gets done

I agree...I don't even use pre-filter sponges on my pumps. My tanks maintenance includes, blowing off the rocks, vaccuming detritus, good skimming, and weekly water changes. :)
 

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