Nitrates through the roof, please help?!

[grafgever]

Hi there, my nitrates have been very high even though I change the water 10% every 2 days after finding nitrate levels above 100ppm, now levels remain above 50ppm and don't want to go lower. My SPS has partly died off and doesn't look very happy. I removed some filter bag from the tank as I don't know what this does and thought it might be making things worse, I've been dosing no3-po4 of Red Sea without success, tank is the rsm 250 salinity is around 1.026, other parameters are all normal. I added a movie of the tank and a picture of the filter bag I removed, it contains mostly brown and some white balls.

http://www.youtube.com/watch?v=GG05rCGYECI&feature=youtube_gdata_player
http://db.tt/qdNIkDMT

 

[downbeach]

What are you using as a skimmer? Did you get a second opinion on the NO3 test?

 

[grafgever]

Hi there, did not switch the skimmer so it's the stock skimmer, it does fill with dirty water though so it's working quite well. I got the water tested at the shop with same results, although they used the same brand for testing. When I test the water in the tank I use for water changes the nitrate levels show very low, almost no coloration. I use the Serra test kit. I got quite a heavy load of fish, in hindsight a bad idea, but decreased feeding a lot. For cleanup I got a large Shelless snail, sea urchin 2 starfish a crab and 3 shrimp, maybe this is insufficient and I need to add more? Also could you comment if removing that bag I posted in the link above was a good move? I'll keep up with the waterchanges, I was thinking maybe I should add more lives and to form a dsb?

 

[fazilosman]

+1 on a second kit to confirm the reading. The white balls look like calcerous worms of some type that you will find in a sump or overflow. My tank has tons of them and they are filter feeders and not harmful.

Are you missing any animals? Could something have died behind the rock and be decaying? That's quite a bit of rock and does not look to have a lot of flow through it. At this point, I would focus on a few things:

1) Make sure you are able to clean between and behind your rock work. Specifically, get a power head and flex tubing, this works well to blow between and behind the rocks. Try to get all detritus out with a weekly cleaning.

2) After cleaning the rocks, I would suggest lightly siphoning the top layer of sandbed. You may need to do this in sections as to maintain proper biological filtration and not disturb the entire bed at once.

3) Is your skimmer tuned properly? Make sure that it is tuned to pull sufficient "gunk" out of the water. For the near term you can set it to skim wet and thus export more nutrients. I suspect that your skimmer is not exporting the bacteria from your dosing which is then simply decaying and causing more nitrate.

4) Check your flow... Specifically, make sure that you have enough flow in the tank to keep detritus suspended so that it can eventually overflow into the sump. Make sure that you remove and clean all sponges, socks and any other items in the flow path as it makes its way through the sump.

5) Test your replacement water and make sure it has 0 nitrates. Hopefully, you are using RO/RI and a good salt mix.

6) Know what you are putting into your tank! This includes food, additives etc. As things break down, they will contribute to Nitrates eventually.

Lowering your Nitrates will take some time... Be patient and also lower it over weeks. Basically, you should be try to keep things as clean as possible right now. Dont try to clean everything all at once. Stage the process, rock and sand one day, socks and sump another, filter pads and bio media another etc.

On my own tank, which is now 3 months old, I use biopellets, vinegar/kalk via ATO, water changes, refugium (caulepa) and good husbandry. My Nitrates started at 25ppm after the cycle and over the last 2 months are now at 5ppm. I obviously would like a lower number but at this stage, I have no visible algae and the corals are looking OK.

 

[grafgever]

First of all thanks for your great reply.

I have an extra powerhead which is hanging in my RO/DI saltwater for waterchanges, I keep about 100L on backup. I could use this powerhead for cleaning like you said, I never cleaned behind the rock work. I do shuffle the sand with my fingers everytime I do waterchanges. I ordered an extra Vortech MP10 which is on the way and I think will help also.

I will turn the skimmer up more, how full should the collection cup be after 24H? I use Coral Pro Saltmix which I read was quite good. I think I had a Salarius that died and I never found, but all other dead fishes I took out and threw away. I try too feed my fish very little but I'm a bit afraid they would starve or something.

I will use your advice and use a powerhead to clean behind the rocks. Do you think some new quality live sand would help?

I was also thinking of buying the Salifert Nitrate test

 

[bertoni]

Also, have you tested nitrite? A small amount of nitrite can show up as a large amount of nitrate when running a nitrate test. It's a limitation of the testing methodology. Some RO/DI should measure at zero if the test kit is okay.

If the test kit seems to be providing reasonable numbers, I'd stop all feeding, and maybe move to a 15% change once a day for a while, to try to save the animals. Normally, water changes are at best a temporary bandage, but when corals are dying, they might be worth the time and effort.

The list above has some good ideas. I'd especially check the skimmer. I don't know how good the stock skimmer is, but I'd consider upgrading.

You might want to get a phosphate reading, too. Phosphate can cause a lot of trouble with stony corals.

 

[mbg75]

Some Chaeto with proper lighting would drop the nitrates down easily.

 

[fazilosman]

Bertoni makes a good point about nitrite which can skew nitrate readings. I forgot about that... In terms of skimmate production, there is not really a known quantity. Instead we focus on quality in terms of color, smell and overall nastiness. Dry skimmate is very dense, green/black in color and very smelly. Wet skimmate is watered down, typically golden/brown in color and less smelly.

The quantity depends on how much organics is in the water and how productive your skimmer is. Many things go into this including reaction times, air flow etc. In general lightly stocked systems get about a 1/4 cup per day depending on feeding etc. I would search for your skimmer make/model here on RC and figure out if anyone has tips for tuning that bad boy. See -> this link on YouTube


I use a ReefOctopus 3000-INT skimmer and figured out everything from the threads on RC. The product manuals are great for initial setup but then RC is great for tuning and getting quick experience with the skimmer.

I would hold off adding anything else to your system right now. If you have lots of organics decaying in the sand bed, then adding live sand is just going to bury these and possibly cause hydrogen sulfide issues down the road. Be very careful about your sand bed and do proper maintenance on it. If either becomes a huge biological filter or massive decaying nutrient sink if not setup correct. (This is my opinion based on a lot of reading).

To help keep the sandbed clean, you must introduce some critters that live in and consume food from the bed. There is a YouTube video by NYSTEELO that describes setup and also maintenance. I have introduced, mini stars, bristle worms, spaghetti worms and various snails that live in my sand bed and thus keep it stirred up and moving. Additionally, I have a Christmas wrasse that also beds down in the sand at night.

Again, there are many forums on sand beds here on RC. I would encourage you to read them and head the advice. In short, you are on the right track - listen to folks like Bertoni, Randy, Sushi Girl and you will be fine.

 

[grafgever]

Thanks for the many great comments guys! I did clean of my tank yeasterday with the powerhead and hose technique fazilosman recommended. After finishing my tank was so white with stuff I couldn't see any fish anymore, but it soon settled and water is very clear again now. I upped the airflow on my skimmer a bit to see if it takes more dirt out of the water. I added 2 pictures of what the skimmer looks like after about 2 days skimming.

Today I received my Vortech MP10 in the post, which I immediately installed in the tank, my SPS corral seems to be happy. 4 out of 6 parts of the coral have died off but the last 2 are constantly out with their tentacles and look in good shape.

I have quite a high bio-load on the tank, I was reading up about the Chaeto idea, but seeing as I don't have a sump and have Tangs in the tank (who eat Chaeto I read), I'm not sure this would work out very well?

As for the sandbed, after about 2-3 days there is quite alot of dirt on the sand, like brownish areas etc. I only got one starfish that lives in the sand, used to have 2 in the start but one died. What would you recommend me adding to the tank for better sand shifting/cleaning? I always stir up the sand with my fingers while I do the water changes as well. Right now my cleaning crew consist of one large snail (no shell), an Urchin, 2 crabs (1 of which I never saw since I bought it, but I assume is in the rocks somewhere), 3 shrimps and another orange starfish that goes over the windows/rocks. I was thinking to maybe add some fresh livesand to the tank, as some areas in the back of the tank seem to have no sand on them.

 

[bertoni]

Stirring up the sand will kill small animals that live in it, and likely damage any microbial residents, as well. I wouldn't do that. There are companies that sell stocking kits for live sand beds, although they tend to be pricey.

 

[grafgever]

Hi again, I have added some new sand to the tank. The guy in the shop seemed very knowledgable and recommended that I suck the dirty spots in the top layer of the sand away and add new sand.

The sand I used: https://www.dropbox.com/s/fsf43dstay25rdd/2012-10-25%2018.10.29.jpg

how it looks in the aquarium:
Before:https://www.dropbox.com/s/1eog3tzna14ej7p/Photo%20Oct%2025%2C%2013%2025%2045.jpg
After:https://www.dropbox.com/s/w8nnyefo5ga8m6m/2012-10-25%2018.10.36.jpg

I also did a 15% waterchange, as Nitrates were again high, between 25-50ppm. I tuned the skimmer according to a post from RedSea on this forum, and will check tomorrow if it skims more. I also added 2 more starfish that live in the sand, so got 3 of those total, which according to the seller should be sufficient for this amount of sand. There is alot more sand in the aquarium then there was before, but it's still between 1-2'' so not too much I think?

Finally I bought some marine bacto that according to the man from the shop eats the dirt that seemed to have gathered in my sand before, and should also help lower the nitrates, I also went to feeding only a quarter frozen cube of food per day instead of half, hope my fishes will have enough?

Ow and before I forget: Nitrite was unmeasurable so near 0, same goes for Ammonia, Phosphate was a bit high about 1ppm, but should be lower already after the 15% waterchange I did.

 

[bertoni]

If you have sand-sifting starfish, they will eat any small animals in the sand, and then starve to death. I'd probably remove them, if that's what they are. Some of the very small starfish (an inch across or so) are fine for eating detritus, but the larger ones aren't useful in maintaining a sandbed, although they can be fun to watch.