Will it hurt my fish if i do a 75%water change to try and reduce NItrites and other bad levels.?

Question

My Nitrates are very high and I have done 2 30%water changes and still no effect. What will it do to my fish if I do a 75% water change to try and keep the fish I have alive. I have lost 3 in the last 2 days.

Answer 1

Please don't listen to the people saying it will be fine. It won't. It can actually make your nitrite levels worse in the end.

When your tank is cycling it is trying to achieve a biological balance between fish waste and beneficial bacteria. When you set up a new tank, there is no fish waste and no bacteria. You add a couple fish which produce a little ammonia (waste) and your bacterial level grows to accommodate these fish and turn the ammonia to nitrite to nitrate and then your tank is considered cycled. When you do large partials or too many partials you are replacing a lot of the cycled water with brand new water with no beneficial bacteria in it. So your tank has to cycle itself again and you will see the same process- spikes in ammonia, nitrite, then nitrate. Since you have already done 2 30% partials, which was a little much depending on how close they were done, doing another large partial will probably just cause a spike in ammonia, then your nitrites will be back up again. The best thing to do is small partials every few days to dilute the nitrite without replacing so much water that your tank has to constantly re-cycle its bacteria population. Try adding some slimecoat and salt for your fish to protect them from the high levels. Prime would help make the nitrites less harmful to the fish temporarily, it will not remove them though. Also it depends on the size of your tank and the kind of fish you have. Hopefully its not a small tank with dirty fish.

Look up some articles on www.wetwebmedia.com. They are EXTREMELY helpful- my 'bible' actually haha. Good luck.

Answer 2

What are your current levels? I assume you have a fairly new tank if you're results are high. The levels should be ammonia and nitrite less than 0.5 (if you're tank is still cycling) and the nitrate should be kept below 40 ppm.

First, are your fish still showing signs of distress (gasping at the top of the tank, lethargy, loss of appetite)? If so, you need to continue water changes.

Do you use a water conditioner designed to neutralize ammonia, nitrite, and nitrate? Normally I don't like using these, because they have the tendency to bind these compounds, but they're still in the tank (in a less harmful form). but still show up on your water tests.

Did the levels come down at all after the first two changes? If not, or if they only came down a little, you might need to continue to do water changes - do this without the conditioner, if you use one that neutralizes the ammonia, nitrite, and nitrate - you need to find out what your levels here really are! Do a 50% change this time and see if it will make a difference. Just add the replacement water slowly, so you don't shock the fish with too fast of a change in their water chemistry.

Also, be sure when you do the changes to use a gravel vacuum to remove any debris from the gravel (this is another source of ammonia as it decomposes) and don't overfeed the fish - only give them what they can eat in 2-3 minutes, twice a day.

Answer 3

Changing more then 50% of the tank volume runs quite a few risks. By changing out over half the tank volume, you can easily shift the temperature and the PH in your tank by factors that will be just as bad or worse then the nitrites you are trying to deal with. It does sound like your tank is still new and cycling, so you don't have a greater risk of shifting the PH as generally older more established tanks have a slightly lower PH. However the temperature in the tank is very liable to be shifted anywhere from 5-10 degrees I'd suspect. And based on that I'd say chances are you will do more harm then good.

If you are trying to bring nitrites under the stress and lethal range, try doing a 50% change and the next day do like another 30%. Don't change that much all at once. Take a reading the day after you do a 50% and see how that leaves you.

Answer 4

Large water changes can be dicey.If you pH has slipped low and you raise it suddenly it can create toxins (Nitrites) that will kill fish. Here's something to check,what's the nitrate content of your tap water? Continue with the smaller water changes. If your tap water is too high in Nitrates there aren't any cheap solutions. I've never heard of high Nitrates killing fish,have you checked the other parameters? Ammonia or Nitrites are the usual suspects.
I know it's difficult to watch, but sudden changes can do as much harm as not doing anything. Be patient and try to get ahead of your problem slowly.

Answer 5

I would recommend "Cycle". It will speed up the process. It is adult bacteria that is able to reproduce quickly to bring down your nitrate, nitrite, and ammonia. Keep doing your water changes. Put more cycle in each time. Don't worry you can't over dose on it. I would change 25% morning and 25% at night also. Keep the water as close as you can to the same temperature. Mostly keep your lights off so there not stressed as much. DO NOT FEED THEM!!! They will be fine if you feed them a little every other day untill your water is in the clear.

Answer 6

it all sounds like good advice.....i found adding some of my old filter water to a new tank will kick start the process...if you have a friend with a large canister filter and some healthy fish you might want to try adding the dirty filter water (your tank will look gross for a coupla hours or over night) the bacteria from his filter should now be in yours.

Answer 7

don't know if this helps, but I am new at saltwater (was great at brackish though). I have two puffers and was able to lower my nitrate WAY DOWN buy planting mangrove pods in my tank. I had to order them on eBay, but it was worth it. They are the king of nitrate suckers. Another one I tried was parrot feather (myriophyllum). go to the link and let your nitrate stress ebb away like the ocean tide.....aahhhh......

http://saltaquarium.about.com/cs/nitratecontrol/a/aa051398.htm

Answer 8

wow.. no i wouldent think it would hert them to much.. but, i couldent be sure, it depends on what type of fish.. and when was the last time you did the 2 30% water changes? it all depends..

Answer 9

Yes. How big is your tank and what kind of fish, filtration, etc., do you have?

Answer 10

Nope not at all.Your going to be fine.