Tropical Fish Keeping - Aquarium fish care and resources

Tropical Fish Keeping - Aquarium fish care and resources (
-   Beginner Freshwater Aquarium (
-   -   Trouble keeping nitrate levels in tank down (

scottysgirl 01-10-2007 12:40 PM

Trouble keeping nitrate levels in tank down
Hi, I have a 30 gallon tank which contains 3 blue rams, 1 dwarf botia, 2 kuli loaches, 1 angelfish, 3 raspboras and a dwarf puffer. I vacuum the tank and do a 20% water change about once every two weeks. There are a few plants in the tank although I have had a hard time keeping plants alive, they all want to die and pollute the tank. There is now more light in the tank and some added plant fertilizer. My main question is: why are the nitrate levels in the aquarium (which has been set up for about 4 months) stubbornly refusing to go down. Nitrite level is 0, but nitrate level, while still in safe range according to testing kit, is borderline and refuses to go down (I will check later and see what the level is exactly.) The tank is at 78 degrees and all the fish seem perfectly healthy and happy, the water is extremely hard. Does anyone have any ideas about what is going on?
Thank you

Jaysn 01-10-2007 02:54 PM

What plants were you trying? I'm having really good luck with anarchis and java fern. Another alternative to plants is to use a nitrate absorber. I used Nitra-zorb when I was cycling my 55, it wasn't going down fast enough for me.

scottysgirl 01-10-2007 03:00 PM

The nitrate level is around 25, and has been consistently there for a long time. I don't know the names of the plants. One is a bulb with long slender leaves, and another is a bulb with dark spade shaped purple leaves, there are five other plants in there right now, one looks like a hornwort but it is not, and I don't know what the others are.

Lupin 01-10-2007 04:49 PM


Originally Posted by scottysgirl
The nitrate level is around 25, and has been consistently there for a long time.

But 25 ppm is IMO fine.:) At least, it didn't exceed to over 40 which can harm the fish.

another is a bulb with dark spade shaped purple leaves,
Sounds like Nymphaea lotus.

Derek-M 01-11-2007 03:27 AM

Hi scottysgirl

Have you checked the nitrate level on your tap water? as you may find that it has traces of nitrate...It is not unheard of to get up to 40 ppm nitrate coming from the tap water especially in rural farming areas

bettababy 01-11-2007 03:50 PM

A nitrate reading of 25ppm is normal for an established tank with water changes only every 2 weeks. If you increase the number of water changes to once/wk, you may see some fluctuation, just don't gravel vac everytime you do water changes, so you don't disturb too much of your bacteria culture.

If there is waste in the tank that is being broken down, from ammonia to nitrite to nitrate, what you are seeing is a "balanced" system, where nitrates maintain a specific level. This means that your tank is stable with the amount of maintenance you are doing and the amount of waste going into the tank. As the fish grow, you will notice an increase in nitrate levels over time because the amount of waste will increase.

As for the plants, it sounds like a matter of insufficient lighting and possibly not enough nutritent level for that species. Nitrates isn't the "only" thing plants need to live. I would say check the light and the types of plants you are trying to keep... some plants need less light, some need very strong light, some need heavy nutrient levels, some need lower nutrient levels. Just like with the fish, the plants have specific needs also. Also check temps... some plants do better in warmer water, others in colder.

Can you describe what the plants are doing? Are they turning yell, losing leaves, "melting away", turning brown, holes in the leaves, etc etc?
I can do quite a bit of troubleshooting if I know the type of plant and the symptoms and current conditions.

Hope this helps...

scottysgirl 01-12-2007 08:45 PM

Thanks for all the help and replies everyone! We do have about 15 ppm nitrate in the tap water naturally, we do live in a farming area. The plant we had the most trouble with was a 'hornwart' it pretty much seemed like it desintegrated, turned brown and died all the way down to the base. Our dwarf lilly bulb started turning kind of transluscent and gross looking and then a leaf fell of. We are fertilizing the plants (just started) and also added another light. We also have 7 Vals in the tank and a crypt and a tall bulb flower, looks like an onion, Cambium or something like that. We just got these recently and the still look fine. The water temp is 78 degrees.

St6_Devgru 01-12-2007 09:44 PM

maybe your fertilizer is not aquarium freindly? maybe snails are eating your plants? mines does until my yoyo loaches iradicated them. you should cut all the dying plant parts as they will regrow.and if the roots arent that long, maybe cut alitlle on the bottom stems as some of the stuff in side willhave been dead and cant soak up water, etc.

Lupin 01-12-2007 09:50 PM

If the ferts weren't aquarium-friendly, the fish would have died.:shake: What brand of fertilizers were you using, Scottysgirl? How many watts per gallon do you have for lighting? Insufficient lighting could also be one of the factors.

bettababy 01-12-2007 11:48 PM

Knowing now what plants they are, what the symptoms are, and some of the tank stats, I can already troubleshoot some of the problem.

Hornwort: Did you plant it into the substrate or float it? Hornwort does best when it's allowed to float because it likes A LOT of light, and it also likes a HEAVY nutrient level, which you don't have. Ferts may or may not help the hornwort, it will depend on what's in the fertilizer and what form it is in. Hornwort absorbs it's nutrient level directly from the water column instead of a root system like most plants. I have the stuff growing out of my ears within a month after putting it into my tanks... but I also stick to tanks with a heavier nutrient level... The last bunch I started was 12 inches long when I put it into the tank. When I pruned it 3 months later, that single strand of hornwort was then 6 feet long, soft, and bright pink on the tips. Anytime I have ever tried to "plant" or anchor the hornwort down low it has died. The deeper the tank, the faster it died.

For the lily, I will have to look it up... I know those symptoms but am not coming up with the cause off the top of my head. I have it in a book, will reply again after I get time to look it up.

With the val: They like to be CROWDED, so plant them in a group together, and if possible, increase their number by as many as you can. Groups of 5 planted close together with more groups of 5 will tend to thrive. Vals also like a lot of light, so be sure they are not shaded by other plants. The extra ferts should help the vals, too... but keep in mind, val is known for its heavy shedding, and is a "messy" plant, even when its healthy. You'll want to be sure to skim any debris from the surface of the water on a regular basis, as this can also effect nutrient levels in the tank.

What crypt are you keeping? Can you post a pic? Most of the crypts will do better with lower light, so if they are shaded by taller plants, they usually do pretty well. If it's one of the "red" species of crypt, the tablet fertilizers with Iron in them are the best thing to use. With the tablets, simply break 1 tablet into a few pieces and insert a piece into the root structure of each crypt plant once/wk. Serra makes a good one called "Flourenette A". It is the iron content in the plants that makes them red, and a typical tank doesn't have enough iron in it to keep the plants well fed and bright in color.

I'm not sure about the other plant you described... is it possible for you to post a picture for us? If I can identify the plant I can get the information about it, but I need to at least be able to see it to identify it properly. The onion plant family, aka Crinum, is usually a pretty easy plant to grow. It likes a bit less light than most others, like the crypts, and they can produce some awesome flowers at the surface when healthy and growing well. There is some good and accurate information here for you about the onion plants:
I hope this was of some help to you, I will post again once I find the book about the lilys and what causes those symptoms. I know what page its on, just gotta find the book, lol.

All times are GMT -5. The time now is 07:59 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

For the best viewing experience please update your browser to Google Chrome