[Ladydi919]

Tank has been established over 1.5 years. Most recent marine reef lab test had extremely high nitrates. Cleaned the filter, changed the carbon filter, also do 10% water changes pretty much weekly. I read somewhere that 10% water changes really won't alleviate high nitrates. That I should make up a 20 gallon bucket of saltwater, remove 10% of my tank water into the new saltwater bucket, then replace with that water and do this approximately 3x. Has anyone ever heard of this, or does anyone have any other suggestions on how to lower my nitrates. HELP, PLEASE

[msbdiving]

I would be real careful about doing any more than a 50% change. You still need to have the bacteria present to keep from cycling all over again (ammonia spikes). You might want to check the nitrates again. What method are you using (titration or strip test) and what levels are showing? How many times a day are you feeding? What all is in the tank, I assume it is a 20g?

[glampka]

If you have a canister filter they are known to be nitrate factories since most people don't clean them enough. Really no need to feed your fish every day. Fish in the wild don't eat every day. They tend to pick. You are correct about the 10% water changes. They don't have much effect. Here's a method that works to reduce niitrates. I have used it with no ill effects: An Instant Nitrate Reduction Method - A Multiple Step Water Change Procedure

[jgo1973]

Hello,

My 150 gallon tank has been running smothly for a year +, a few weeks ago my nitrates jumped up to over 100. I did a 20% water change and it didn't budge. A few days later I did a 50% water change and that lowered it to 80. One week later I did a 60% water change and just yesterday I took my water into a professional to have it checked and my nitrates and ammonia are both 0, and everything else in normal range.

During the few weeks of the water changes I also got some CAULERPA, it is a "sea weed" that eats nitrates. I simply rubber banded it to a couple of my live rocks and that is suppose to help. I don't know if it did, but we are all good now.

Good Luck!

[poccoe61]

wouldn't that instant nitrate reduction level cause you to remove all bacteria...leading to an ammonia spike?

[Ladydi919]

Thanks to everyone who responded. Glampka checked out your link. Will try that method in the AM. Thanks again, everyone here is a much needed wealth of information.

[marciemp]

I don't think the good bacteria is located in the water, more so in the filter media, the live rock and the sand. Changing a lot of water can be hard on the animals, but shouldn't lead to an ammonia spike, as long as the tanks live rock, sand and filter are fully established. Sometimes it is neccesary to change a lot of water, like when you move a tank, or have big problems with the water quality, it just should't be done too often

[glampka]

You will not remove the bacteria since it is resides in/on the rock & sand. When doing a large water changes like this it is very important to be sure that the temperature & salinity of the new water matches that of your tank to minimize any stress.

[pogodzib]

A water change diluted the nitrates. If it was at 100ppm and you did a 20% water change using newly made RO/DI saltwater that has 0ppm nitrates, your tank will end up with 80ppm nitrates. However, if your tank has 40ppm nitrates and you did a 20% water change using tap water that has 20ppm nitrates, you will end up with 36ppm nitrates, which isn't too much of an improvement. When you do water changes, make sure that your new water is pure (salt)water and contains no nitrates otherwise you'll never get down to zero. Also, like already stated, certain types of filters (power filters, caniser) along with bioballs are know to be nitrate factories and should not be used in reef tanks unless cleaned very often. Even then, a better way is by using only a skimmer and live rock/sand (1-2Lbs/gal) for filtration.

[poccoe61]

eh i don't use a skimmer. i might look into purchasing a nano skimmer of some sort though. i don't really test for nitrates as my test kit only comes with ammonia/nitrite testing supplies. perhaps i shall though. anyway i do about a 20-25% water change biweekly (or if its necessary for any other odd happenings). keeps the water pretty much crystal clear, and algae free (THANK GOD...i battled with algae for the first 3 months of this project).

i must be doing something right. thanks for the info on bacteria

[Krazy]

Check out this article..

Lower those Nitrates!