Controlling Nitrate Levels

[mark4785]

I currently have a 120 litre aquarium stocked with sensitive Blue German Rams and a few other Dwarf Cichlids that can only thrive in low concentrations of nitrate. They have been in the aquarium for only 48 hours and the nitrate has climbed to 10.0 ppm.

I've heard that 20.0 ppm is the point at which a 20% water change and gravel clean should be conducted to reduce the level. So I did just that, removing about 20% of the water and doing a gravel clean where I thought most of the dirt would be. Afterwards, I obtained some warm de-chrorinated water (about 27-28 degrees C) to add back to the aquarium which is also at this temperature. I did another nitrate test using an API freshwater master test kit and the level was seemingly somewhere in between 5 and 10 ppm. To be honest, I was hoping and felt strongly that it would be 5 ppm or lower.

I opened up the aquarium filter box manual in order to ascertain how frequently it is advised that a Cayman Bluwave 05 filter system should be cleaned and it stated a 2-3 week clean with a brush in a bucket of tank water is needed. The aquarium has been running now for about 6-7 weeks and the outlet pipe is still churning out water at a fast rate; despite this, should I consider dunking all of the filter media in a bucket of water; is this where the nitrate builds up?

The manual also states that demineralised water should be considered when topping the aquarium up after water changes. Is demineralised water the same as RO water produced by specially designed filtration machines such as this thing?.

I'm not sure whether nitrates in my tap water is not helping with this situation so I'm eagar to know if a RO water machine would remove the nitrates?

Mark.

 

[Davo86]

Nitrate is the end product left over after the filter bacteria has broken down the harmful ammonia and nitrites, You remove nitrate by performing water changes

RO is more for Marine systems and IMO is completely pointless in freshwater

 

[mark4785]

Nitrate is the end product left over after the filter bacteria has broken down the harmful ammonia and nitrites, You remove nitrate by performing water changes

RO is more for Marine systems and IMO is completely pointless in freshwater

Ok thanks,

What should be done if high nitrates are present in the tap water then? I've heard 20 - 40 ppm of nitrate can be present in tap water, something that German Blue Rams don't tolerate.

 

[Mikaila31]

I kept and actually unintentionally spawned GBR in my tap, which has 20ppm. The tanks read higher then that, and they actually spawned when I was 2 weeks behind on 50% water changes. As long as you get well bred GBR I have not had a problem with them. I've never even seen a 5ppm reading on any test kit. So your water is great IMO. If you find local bred fish you should have no problem spawning them in my experience.

 

[arobinson1984]

Your water doesnt seem too bad if you are getting a reading of only 10ppm in the tank.

Live plants will help slightly lower nitrates if you have enough plants in the tank and they are healthy, on the other hand, unhealthy dying plants will higher nitrates as leaves rot and create ammonia which will eventually process through to nitrates etc.

In my experience, german blues ideally need below 20ppm but can quite often be ok upto 30ppm so if you have low levels in your tap water than a good weekly 50%+ water change should keep the levels at a suitable level.

Bolivian rams are slightly less sensitive and should be ok upto about 40ppm


Andy

 

[mark4785]

I kept and actually unintentionally spawned GBR in my tap, which has 20ppm. The tanks read higher then that, and they actually spawned when I was 2 weeks behind on 50% water changes. As long as you get well bred GBR I have not had a problem with them. I've never even seen a 5ppm reading on any test kit. So your water is great IMO. If you find local bred fish you should have no problem spawning them in my experience.

Thanks for that Mikaila. It sounds like GBR aren't as sensitive as some make them out to be then. I still want to ensure I don't get a nitrate reading above 20 ppm just to be on the safe side. I'm finding it hard to reduce the level though.

Your water doesnt seem too bad if you are getting a reading of only 10ppm in the tank.

Live plants will help slightly lower nitrates if you have enough plants in the tank and they are healthy, on the other hand, unhealthy dying plants will higher nitrates as leaves rot and create ammonia which will eventually process through to nitrates etc.

In my experience, german blues ideally need below 20ppm but can quite often be ok upto 30ppm so if you have low levels in your tap water than a good weekly 50%+ water change should keep the levels at a suitable level.

Bolivian rams are slightly less sensitive and should be ok upto about 40ppm


Andy

Thanks Andy. The next water change will be larger (50%) as per your advise. I have 3 tropical plants within the aquarium, they appear to be very healthy so I don't think they are contributing to highering the nitrate level.

 

[Davo86]

As said, Very quick growing plants like vallisneria and hygrophilia sp. will help to use up these excess nutrients

 

[N0body Of The Goat]

A significant amount of fast growing plants in your "water garden" can use something like 5ppm of nitrate per day, not to mention they can utilise any ammonia too.

However, this does often mean investing in long-term fertilising substrate under the gravel/sand; 2W per gallon lighting; a carbon dioxide source (possibly a "fire extinguisher" type bottle with controlled bubbler); daily fertiliser spray.

The cheaper but more hands-on appraoch is to do more regular, larger percentage water changes, but then you do need to be aware that most water authorities often vary the amount of nitrate found in the supplied tap water eg. Southampton's varies 20-50ppm.

 

[OldMan47]

The only reliable method I know of to control nitrates is a water change. I have tanks that were set up on the Walstad model that just never see significant nitrates, but that is a lot to ask for a new person trying to control nitrates without the plant experience to back them up.