Hi All,

I've got a 15 gallon planted biocube (housing two small guppies) that's about six months old, and has never really been "right." I'm becoming increasingly frustrated as it looks worse and worse, and would appreciate some assistance in trying to get things back on track.

My problems are that the tank has diatoms, a lot of algae, and the plants just won't grow. I'm not really sure where to start to please bear with me.

The water parameters are where they should be. Amonia and Nitrite always test zero. Nitrate tests under 20, usually around 10, although with the API kit it's diffilcut to tell the difference. This tank has always done a great job at biological filtration; I've never had any issues.

I'm not thrilled with the tank's mechanical filtration. Although the outlet from the filter gets a pretty good current going, it just doesn't seem to circulate and filter particulate matter all that well. That said, things are not particulary dirty when I vacuum the gravel. I change the carbon filter monthly, and I've cleaned out the sponge filter a few times without any real change in behavior.

The tank was setup with 3/4" Eco-Complete substrate, with about 1/2" of CaribSea Instant Aquarium on top. Originally I would say it was moderately planted, with a sword, a mirco-sword, some anarcharis, some cabomba, some floating hornwort, and a few other plants. None of them thrived, and at this point the only plants left are the sword and another similar plant I can't remember the name of. They grow, but very slowly. At one point, the sword grew another 'bulb,' which I re-planted, and while that's alive it's barely grown. I've even tried a few root tabs, which didn't help.

The tank came with lighting for a reef, but I did track down 18W 6500K bulbs. The tank can run one or two bulbs; originally I had both on for 12 hours a day, which generated a ton of algae. I've since cut down to one bulb, 8 hours a day, and I'm not sure that's actually helped at all.

The plants have had green carpet-like algae in the past. Currently they have thick black algae at the pointy edges of the larger leaves. I also have some stringy algae all over the place. That was worse when the hornwort was in the tank; since removing it there is less of the stringy algae but it's still there.

Basically then, I need some direction. What should I do to fix things? I'm open to any suggestions even if it means ditching all the plants and buying new, etc. Whatever will work best and give me a tank that's visually appealing.

Thanks very much.

Endaar

What sort of fauna is in the tank? What type of maintenance do you perform and how often?

Just the two guppies, plus a couple of random snails that rode in on the plants.

I'm doing 20% water changes (with vacuuming) every 2-3 weeks, changing the carbon filter monthly, and trimming the plants as needed, which isn't often.

James

I would suggest running co2 and getting some larger snails. What is the pH of your tank?

__________________

29g Tall FW: Many Swordtails: 1 lemon, 6-8 neon/pineapple, 1 Gold Tuxedo, ? fry; 1 Clown Pleco; 3 Otocinclus Cats, and MTS.
Planted: Amazon Swords.

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