Plants not growing very well


So, I had a 10 gallon (38 liter) tank for some years and upgraded to 20 gallon (75 liter) tall about 20 years ago. It came with undergravel filter with gravel, which is still there, and carbon and 'ammonia' cartridges, so, that's what the fish lived in up 'til about two years ago. Was originally planted, but the variety of fish I had kept eating the plants, so I switched to plastic. By then I already had quite a crop of Trumpet snails. I used airstones in tubes for the UG filter for a while, then got a powerhead.

Finally, about two years ago, I couldn't get the cartridges any more, so, I joined Fishlore and browsed threads. This prompted me to plant the tank again and get a Penguin Biowheel 150, and took the power head out. Also got the API Master Kit and started testing.

I have a Amazon Sword and a few others, I forget what they are. Test results are very consistent.
Temperature: 75°F±1 (24°C)
Ammonia: 0
Nitrites: 0
Nitrates: 0
Total Alkalinity: 160 ppm (GH 9)
Calcium/Magnesium Hardness 180 ppm (KH 10)
pH 8.0-8.2
Phosphates: 1-2 ppm (occasionally 0.5)
TDS: 300-320 ppm

I don't need to treat for chlorine as the fill water is well water, no chlorine ever.

I replaced the old fluorescent hood with a glass top and a Nicrew ReefLED light, 6 hours white/yellow, 1 hour blue, gradual on and off.

The trumpet snails thrive, I don't mind them. Tried a few Apple snails, they don't do well, I believe because the pH is a bit high for them. I may try Nerites sometime, if I can find 'em.
Current fish: 5 Neons, 5 Black-skirt tetras, 4 Platys (was 5).

The community seems to do quite well except the plants just don't seem to grow, and have lost a few in the last year. I would like to plant more, but, not until these start growing better. I know I have quite a bit of algae, the black and white gravel is mostly black and green. I also have a bit of diatoms; that seem to start when the plants were introduced.

Currently, I got some root tabs from PetSmart, don't know which brand. It says a tab per month, but, it just made more sense to put some in each water change, so, I cut them in quarters with a pill cutter and put one in the gravel after each weekly water change. Seems it would be more consistent.

So, I browse the forum and have gotten quite a bit of knowledge from here. I would like to thank everyone for input to others that I have been able to learn from.

So, here's my question. It seems my chemistry is within parameters to allow the plants to grow, but, consistently I get zeros for the ammonia/nitrite/nitrates. Besides the root tabs, seems to me this is what the plants need, just not quite enough bioload. The biowheel stays pretty clean, no buildup (itdoesn't turn most of the time because a snail got in there when it was tiny, grew up and died in there making it off balance). I'm thinking I need to get some sort of fertilizer to add to the water weekly to make up at least the nitrogen portion, the phosphate is probably OK, it comes in the fill water.

Just wanted to see what others think. Thanks in advance for any input.


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The plant in the second picture is java fern ‘windelov’ - do you have it planted in the gravel or sat on top of it so the rhizome is exposed?


I use Thrive root tabs every few months and Thrive liquid fert once a week. I have vals, crypts, and frogbit and they all do well. .

My water is very hard and my ph is 8.2. I think the fact that you have 0 nitrates means you need more fertilizer.


I agree with kansas. If your nitrates are consistently zero the problem may be not enough nutrients in the water for the plants to grow. I'd suggest adding a good liquid fertilizer (not Seachem Flourish).


About root tabs- they slowly release the nutrients over the duration of a month. Cutting them up and dosing once a week isn't going to make it "more consistent."

Anyways, yeah, you definitely need more nutrients, either by replacing your substrate with soil-based stuff, or dosing with a good liquid fertilizer (aka, not Seachem Thrive unless you want to buy half a dozen other bottles of products to supplement what it lacks).

You also seem to have quite a good bit of algae, so it may be wise to buy some more plants when you start dosing more ferts. It doesn't look like you have many plants right now, so the extra nutrients that they can't snatch out of the water will feed algae instead. Adding more plants, especially fast growers like pearlweed, can help prevent an algae outbreak.


Thrive is not Seachem, it's an all in one made by some other company. I know others use the Easy all in one


Thrive is not Seachem, it's an all in one made by some other company. I know others use the Easy all in one

Yup. Thrive is made by Niloc, and quite a few people like it. Maybe BlackOsprey was thinking of Seachem Flourish?


Yup. Thrive is made by Niloc, and quite a few people like it. Maybe BlackOsprey was thinking of Seachem Flourish?
Yeah, that's it. Got my product names mixed up lol


Thanks everyone for your response. I think this verifies my suspicion. I'm thinking that the Niloc Thive regular as opposed to C, since I have no nitrates at all, the extra in the regular will help, will be ordering some. btw, the only planted is the sword, all the rest are tied to some small shells tied with sewing thread to make them sink. Any that root, OK, the rest I can move around. And as they start to perk up, I can put in some more plants. Ooh! Yeah! That'll give me opportunity to add more bioload (fishies). I love it when a plan comes together.:)


I was running into a nitrate problem as well. Bought a lot of nutrients from seachem and stasrted dosing them regularly and solved the problem. Good luck with it.

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