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Joan, Vet Technician
Category: Pet
Satisfied Customers: 18037
Experience:  Vet Tech for 35+yrs. Small Animals and Fish
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what is a safe level for nitrates in fish tanks? I got told

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what is a safe level for nitrates in fish tanks? I got told they should be 0mmp but I just read they are safe under 40mmp? Mine were 10mmp a few days ago and did water changes and a gravel vac (the gravel vac did need doing but) and now they are around 5-10mmp. I am worried now my tank is going to be too clean. I didn't touch the filter or airstone just the water changes. I don't know what my nitrites are I know they should always be 0mmp. I asked the pet shop for a test kit and they gave me a nitrates. Will my nitrites be ok? My ammonia levels are ommp. When you do water changes is this the right levels things should be I have freshwater tank nitrates- safe up to 40 nitrites 0mmp PH around 7.2? ammonia ommp Its just confusing because I get told different things. I want to also start treating my fish with melgafix as he has a few scales missing, cloudy eyes and a but of fluffy stuff on his head. I don't like treating him with chemicals but the pet ship said too. I wanted to get my water good before I started will it be ok to start now to nitrates and ammonia are ok or should I wait until I buy a nitrites kit to test that? your help would be great thank you


The Water quality should be Ammonia 0, Nitrites 0, Nitrates 20ppm or less and the PH 7.0 isaverage. The best test kit to get is an API Master test kit. It is the most accuarte test kit and it is small containers and not strips. You only need one test kit instead of individual kits.

As far as Melafix, it is a natural treatment male with essential oils and not really a Chemical treatment. Depending if you have catfish in your tank, treating with Aquarium salt is another option that we use to treat fungal and bacterial issues in fish. If you do not have scaleless fish you can use 1 teaspoon of aquarium salt per gallon of water. This helps with stress, injuries, fungal infections and vbacterial issues. Please let me know if you have further questions. My goal is 100% Excellent service. Joan

Customer: replied 4 years ago.
Thank you for your help so the extra water changes I've done should be ok then if my nitrate was 5 :-) Thank you for all the levels for the tank that will be very helpful will get one of those kits tomorrow. Also when the ph is high mine was 7.4 today can you add ph down or is it bwtter to do water changes? i have no catfish in my tank just one large black moor in a 40 litre tank was going to get another fish but with his infection am gong to wait until it has cleared up thanks again


The water parameters are fine and I would do partial water changes to lower the PH. It is better if it can be done with the water changes. The average for gold fish is 20 gallons per fish, so be sure when adding another fish the tank is large enough. The aquarium salt would be good to add as a treatment and is usually very effective. Joan

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Customer: replied 4 years ago.
Thank you, XXXXX XXXXX has been great :-)


Glad to be of help! Hope that you will ask for me in the future if you need assistance. Joan

Customer: replied 4 years ago.

hello I just have one last question. I tested my nitrites today and they were 0, and my PH is good now. I tried to get good look at my fish today its hard but his head does look only slightly fluffy its hard to explain the fluff and his small cut is nearly better. His eyes are only slightly glassy. Should I still treat him with the megafix? Or just keep an eye on it?


Also do black moors change colours do they? Under my black moor his belly is gold no scales are missing just really gold? He is an older fish we have had him a very long time. Thanks for you help.


Fish can change color with age and it will happen if the conditions have not been correct. I would use the salt(only one time because it stays in the water). See it the fish continues to clear. If it does, there would be no need to use the Melafix. if in two days it does not clear or seems to be getting worse, then the Melafix is fine. As I said it is a natural product, and not chemical based, so is pretty safe. Joan

Customer: replied 4 years ago.
Hi Oh ok he wasn't my fish he came from my work where the water was really bad and the kids were over feeding him. With the salt just the salt from pet store and how much do you use? I haven't used it before in a tank thanks


The Aquarium salt is used at 1 teaspoon per gallon of water. Salt has remarkable healing powers. It helps the fish create a natural slime, works on Bacteria and Fungal infections and reduces stress. It is worth trying first and see if it helps clear the problem. I am sure with the water parameters correct, that will greatly improve the fish. Joan

Hi Melissa,

I'm just following up on our conversation about your pet. How is everything going?

Customer: replied 4 years ago.
Hi Joan thanks for asking his cut has nearly better but I am still getting the salt going down today have been checking the water to make sure everything is fine which it is. The only
Problem I have is there is a lot of snails in my tank I asked a
Few pet shops if they would take them I have heaps how can I get rid of them humanely there is so many them I read that they can be a problem in tanks if you don't get them under control other than that my fish is doing very well thank you

Hi Melissa,

The snails came in with something that you put in your tank and are very hard to get rid of. This link has some good ideas which includes placing a plate on the gravel and a piece of food they would like, and by morning you should be able to use your net and remove a load to take to the pet shop: Hopefully thhis will help. Joan

Customer: replied 4 years ago.
Thanks yes it was my live plant I did have a look when I put it in my there must have been some eggs. I will try the lettuce tonight but the pet shops said they didn't want them can they be put in the garden I don't like killing things thanks for your help


No, they can be a major problem with them taking over as a species that does not belong. I am having a problem with them where I live and the worst part is they can transfer Lung worms to other animals. Best to place them in alcohol like a beer which will put them to sleep peacefully die. I have beer traps in my yard to attract them. Joan

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