About two weeks ago I changed the gravel in my established 10 gallon tank. Before the gravel change my ammonia was at zero. Today I tested my parameters and found the ammonia at 0.25ppm, nitrites at zero, and nitrates at approximately 30ppm. My tank currently has nerite and ramshorn snails that are healthy and eating and, for the ramshorns, laying eggs. Before I add red cherry shrimp I want to make sure the ammonia level is at zero. My question is could the gravel change have caused the ammonia to spike? Also, my filter is a three year old air driven sponge filter; should I add another sponge filter to the opposite end of my tank to drive the ammonia level down?
Gravel change and Ammonia level in established tank
- Thread starter bigtom63
- Start date
Yes, its possible the substrate had a large enough portion of the nitrifying bacteria that removing it caused a mini spike. Water changes should take care of it until things level out...adding more filtration couldn't hurt.
Jpappy is correct. If you're not familiar, read up on underground gravel filters. Even just gravel acts like a huge biological filter. Every contour on the gravel has has bacteria growth and the more exposed the area the more bacteria are there. These are the guys that break down ammonia and the rest. If you have a HOB or canister that creates water flow movement no matter how sight, the gravel it moves over supports more bacteria. If you remove the old gravel there goes the bacteria and the new stuff takes a while to get a healthy growth of bacteria on it.
Second thing, don't dig in the gravel! The exposed areas have many more bacteria than those areas not exposed. If you rearrange them the high concentation of bacteria that used to be exposed but is now covered loses a significant amount of oxygenation and the bacteria die off to some extent. When that happens the bacteria release compounds in the water and then rot away cousing levels to spike.
Second thing, don't dig in the gravel! The exposed areas have many more bacteria than those areas not exposed. If you rearrange them the high concentation of bacteria that used to be exposed but is now covered loses a significant amount of oxygenation and the bacteria die off to some extent. When that happens the bacteria release compounds in the water and then rot away cousing levels to spike.
Many thanks for the input. Besides partial water changes and adding a second sponge filter, I am also changing to ammonia absorbent cat litter combined with daily litter box cleaning. This will reduce the possibility of my tanks absorbing ammonia from the air. I am also curtailing gravel vacuuming so as not to disturb the growth of good bacteria. Strangely enough I only realized the cat litter could be a problem when I detected 0.25ppm ammonia in my three year old established, unmodified 16 gallon tank. Armed with this knowledge I can eliminate the possibility of atmospheric ammonia along with improving filtration and not disturbing the gravel bed. Sorry for the ramble but I greatly appreciate all the help-it brings me closer to my goal of a healthy shrimp friendly tank.
The fact about the bacteria is they will colonize any area of a tank with decent flow and not too much light. The best place for this should be in a filter. However, poor filter maint. will push bacteria to be elsewhere. When in the gravel they are in the surface layer, as notd, but mostly on the underside.
If nitrifyers die, they do not release anything into the water any different form other dead matter. Considering all the bacteria that normally lives in a tank, the nitrifying populations are relatively some of the smallest. So I highly doubt that killing off 100% would cause noticeable fouling issues. Of it would cause severe cycling issues.
As for a .25 ammonia reading, as long as the pH in your tank is under 8.0, ignore it unless it fails to disappear in a couple of days or if it rises. If it is not a false reading, the bacteria will catch up in a matter of hours. If it persists or rises then there are likely more critical problems than just losing a few substrate bacteria and these will need your attention.
The amount of toxic NH3 in .25 ppm of total ammonia in a tank with a pH of 8.0 and at a temp of 80F is .0155. This level is considered safe for salmonids which are known to be some of the most ammonia sensitive fw fish. The Merck Verterinary manual puts the redline for NH3 at .05 ppm.
Much as I hate to state this, most people in this hobby have 0 clue about ammonia, nitrite or nitrate toxicity and what makes them harmful or how to handle that.
Consdier this for one moment. You have a big pond full of fish. Lets say its 10,000 gallons and you detect a nitrite spike at 5 ppm. What do you do? Don't tell me repeated 5,000 gal water changes because this is plain silly. And what about aquaculture facilities? There is 0 way to do a water change on a pond that is measured in acres. How do these folks deal with a nitrite spike if they can not change water? Think chloride- do a bit of research on this and you will be surprised to discover that we can handle nitrite in our tanks using plain old table salt which is sodium chloride.
If nitrifyers die, they do not release anything into the water any different form other dead matter. Considering all the bacteria that normally lives in a tank, the nitrifying populations are relatively some of the smallest. So I highly doubt that killing off 100% would cause noticeable fouling issues. Of it would cause severe cycling issues.
As for a .25 ammonia reading, as long as the pH in your tank is under 8.0, ignore it unless it fails to disappear in a couple of days or if it rises. If it is not a false reading, the bacteria will catch up in a matter of hours. If it persists or rises then there are likely more critical problems than just losing a few substrate bacteria and these will need your attention.
The amount of toxic NH3 in .25 ppm of total ammonia in a tank with a pH of 8.0 and at a temp of 80F is .0155. This level is considered safe for salmonids which are known to be some of the most ammonia sensitive fw fish. The Merck Verterinary manual puts the redline for NH3 at .05 ppm.
Much as I hate to state this, most people in this hobby have 0 clue about ammonia, nitrite or nitrate toxicity and what makes them harmful or how to handle that.
Consdier this for one moment. You have a big pond full of fish. Lets say its 10,000 gallons and you detect a nitrite spike at 5 ppm. What do you do? Don't tell me repeated 5,000 gal water changes because this is plain silly. And what about aquaculture facilities? There is 0 way to do a water change on a pond that is measured in acres. How do these folks deal with a nitrite spike if they can not change water? Think chloride- do a bit of research on this and you will be surprised to discover that we can handle nitrite in our tanks using plain old table salt which is sodium chloride.