HELP TO REDUCE NITRATES

[Spiderman]

Hi all,
In my 10-week old SWFO 25G tank (2 clowns, royal gramma, banggai cardinal), nitrates shot up to 25 - from around 12.5 last week - even after a 20% water change this morning (it must have been much higher before then!).

i went to my LFS and they suggested that I make ANOTHER water change tomorrow - using RO water (is that reverse osmosis). Should I do a water change, say 10% each day for the next week so nitrate levels go down to an unacceptable level? Also, what's the best way to clean the substrate using a gravel vac?

Also, I must be overfeeding them, so I'll reduce the amount I'll give them. Any inverts I can add to eat detritus? I have 3 crabs. a cleaner shrimp, and 5 snails.

HELP!

 

[steve-s]

Hi all,
In my 10-week old SWFO 25G tank (2 clowns, royal gramma, banggai cardinal), nitrates shot up to 25 - from around 12.5 last week - even after a 20% water change this morning (it must have been much higher before then!).

Most of the problem here is too much too fast. Once the tank has cycled that's only just the beginning stages of a tank. After the tank has had time to mature and has been set up to deal with the final stage of the nitrogen cycle, (nitrates to nitrogen) it will in time be able to handle the bioload you have now. Unfortunately this takes much longer that 3 months in most cases. Adding too many waste producing animals quickly doesn't allow the bacteria time to catch up to the load. Although the bacteria is present, the number must grow to accomodate the waste load each time it's increased and should be done so slowly.

i went to my LFS and they suggested that I make ANOTHER water change tomorrow - using RO water (is that reverse osmosis). Should I do a water change, say 10% each day for the next week so nitrate levels go down to an unacceptable level? Also, what's the best way to clean the substrate using a gravel vac?

Most fish will be able to handle 25 ppm nitrates for the most part but you should try to bring it down some over the next few weeks. A 10-15% water change every few days should be fine with the RO water recommended. Keep the feedings light and/or only feed every second day to help allow the tank to catch up.

Personally I would never recommend vacuuming substrate of any kind but when doing water changes, fanning the surface of the substrate will help in removing it. It really depends on your overall set up and what is employed to export nutrients on a regular basis other than water changes.

Also, I must be overfeeding them, so I'll reduce the amount I'll give them. Any inverts I can add to eat detritus? I have 3 crabs. a cleaner shrimp, and 5 snails.

I would hold off on any additions until you get the nitrates down some. Most inverts can acclimate to higher nitrates if already in the tank but if going from a low nitrate environment to a much higher one, the differential can sometimes cause fatalities even with carefully drip acclimation.

Once the nitrates are down a bit better I would actually suggest about 5-10 nassarius snails. They are the best at detritus/leftover food bits and will keep the sandbed clean without intervention on your part.

Cheers
Steve

 

[Spiderman]

Thanks, Steve!
Adding live rock won't help in reducing nitrate levels?
Also, what does "fanning the surface of the substrate will help in removing it" mean?
Thanks a LOT!

 

[steve-s]

Thanks, Steve!
Adding live rock won't help in reducing nitrate levels?

Sure it will but you'll need another 25-30 lbs of rock in addition to your 7 already. Denitrification via LR takes place within the rock through the use of facultative bacteria living in anoxic regions of the rock. That is what I meant when I said "and has been set up to deal with the final stage of the nitrogen cycle". LR is but one method though one I personally prefer.

Dealing with the final stage of the nitrogen cycle is only one link in the chain though, DOC being the beginning of it. Reducing the organics within the tank before they have a chance to break down is also a major part of the "scheme" if you will. Wether that be water changes, macro algae/soft coral harvesting or skimming; export of some kind is essencial.

Be sure if adding LR at this stage of your tank developement, the rock is precured before adding or it will crash the tank.

Also, what does "fanning the surface of the substrate will help in removing it" mean?

When you "fan" the substrate or briskly swish the water just above it, the loose detritus and foods are brought back into the water column. Depending on the filtration or skimmer you use if any, this will allow them another chance at removing these organis before they are broken down further. As I said though it's best done when water changes are preformed as it will "dilute" the pollutants at the same time.

Cheers
Steve

 

[seaham358]

My question is what kind of substrate do you have.... If sand then no to the vacuuming if you have CC or gravel type then yes you should vac getting trapped food and waste out of the tank. Doing this on a regular basis with water changes will help keep levels down.