# Aquatic plant fertilizer...is it safe to use?



## danatwh (Oct 10, 2010)

I have a fully-cycled, 10-gallon tank with a few live plants that I have been maintaining for about 8 months. The tank is set up in a room that gets a lot of natural light, though the tank itself is not in direct sunlight. I have one 2" rainbow shark that I am growing out before I put him in the main tank. I change the htb filter and do a 50% water change 1x/month and the water parameters stay about as close to perfect as I can get with this schedule.

Everything is perfect in the tank, except for the live plants. The algae grows fast and I scrape it off the glass weekly, but the plants haven't grown at all since I put them in the tank 8 months ago. I have had these same types of plants in the past with similar water parameters and they flourished before.

I want to give the plants a liquid fertilizer that's supposedly aquarium safe, but I really don't want to risk messing up the the biology of the tank either.

Any and all comments, either for or against using plant fertilizer in aquariums would be greatly appreciated.


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## DJRansome (Oct 29, 2005)

If you don't exceed the recommended dosage and it is a fertilizer designed for aquariums you should be fine.


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## Number6 (Mar 13, 2003)

If plants arent growing then all you would be doing with the plant fuel is growing algae. My bet is that you don't have enough lighting on the tank.


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## danatwh (Oct 10, 2010)

I'm thinking Number6 is probably right that adding fertilizer will probably increase the growth of algae, which I definitely do not need.

I was always under the impression that the more light you have, the more algae will grow. The algae can be seen on the glass within 3 or 4 days after I have cleaned it all off, so I don't think there is a lack of light. However, I almost never use the hood light, so maybe leaving that on during the day would help?


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## Aulonocara_Freak (May 19, 2011)

What type of bulbs do u have?
Are they the screw in type? 
How many watts, kelvins, and lumens r they?


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## Number6 (Mar 13, 2003)

*danatwh*
No, algae thrives when plants can't. That includes insufficient light and too much light.


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## danatwh (Oct 10, 2010)

The light is just a standard screw-in-most-likely-an-appliance-bulb. The room is light and bright and my house plants do great in there, so the problem must be too much light.

When I had live plants before, the tank received no natural light at all, but I did keep the hood light on about 12 hours a day...the plants grew like crazy then.


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## Aulonocara_Freak (May 19, 2011)

How many watts are the bulbs?
How many Kelvins aka k are the bulbs?
How long are the hood light's on?


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## klumsyninja (Aug 14, 2008)

add more plants, you need to outcompete the algae for the nutrients. Stem plants like hygros are good for that.. number 6 is right, if you add ferts you'll just be feeding the algae.

You can also try putting your lights on a timer and have em on for only 8hrs a day.. (because the light cycle might be too long)


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## Anthraxx8500 (Feb 11, 2011)

how exactly are you cleaning the algae up? are you simply wiping it away? or are you taking a razor blade to the glass? personally i take out the ole razor blade when things get a bit too dirty. gives me a great looking surface and it takes the algae a lot more time to regrow. also i think u may want to do a few more water changes. clean fresh water will help your fish show good growth. GL to ya


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## danatwh (Oct 10, 2010)

@ klumsyninja: I only have a couple of plants in the tank, so I think I'll try adding some more. In the past when I had plants in an aquarium, it was pretty heavily stocked and I had minimal algae, so maybe adding plants will help.

@Anthraxx8500: I use an algae sponge scraper that seems to do a good job of cleaning the glass. It would take forever to clean the glass with a standard, 1" razor blade...I would need one at least 6" wide to clean my 55-gallon tanks.

My tanks are all over-filtered and under-stocked, so the need to do water changes is minimal. However, I suppose doing water changes more frequently wouldn't hurt...

Thanks everyone for your insight and ideas!


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## londonloco (Mar 31, 2011)

Plants need a correct balance of light, nutrients and Co2. There are several methods of dosing, all include weekly consistent wc's. Like everyone else here, I'd suggest adding more plants, and leaving your light as is for now, 8 hours a day is plenty of light for planted tanks. But I'd also suggest reading up on different dosing regimes, such as Tom Barr's Estimated Index or PPS PRO ( there are many others out there) and following one to the T including weekly wc's. I have had success adding Excel (liquid Co2) in smaller tanks. I currently have 8 planted tanks set up, it literally takes me 3 mins a day to dose NPK and Excel. Weekly water changes take an hour.


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## Denny (Sep 27, 2008)

Get a small pleco or two Will keep your algae in check and tank clean


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