plants not growing or dying

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Aquarium Advice Regular
Aug 19, 2023
ive been havin tough times with plants for awhile now, i got some sagittaria subulata, a good amount of cryptocoreans,
anubias, and java fern.

the sagittaria subulata has some green/yellow leaves and also melts some leaves away, it looks bad but it never actually dies.
cryptocorean are probably my best plants. they have alot of new growth but they stop growing very quick., the new growth only grows right above my substrate, it literally touches the substrate. it always stays green.
anubias i only got one, a big leafed one from africa i was told. it has that anubias rot after 1 day in my tank not sure what to do about that but it still lives with a few leafs left.
java fern is brown with holes and very straggly looking. Has new growth in it but of course they dont really grow any leafs from it.

my tank is
nitrate=80-100 range
ph= anywhere from 7.5-8 using api drops. api test strips say ph is like 6-7 tho
GH- again api drops =6-7 but api test strip = maxed out 180
KH= maybe 0, drops dont want to work, test strip says 0

i dose with thrive liquid fert/seachem potassium/sechem excel/thrive tablets
not sure what to do really. i feel like if theres no growth with what i have its missing phosphate.. just my idea but i shouldn't be missing it with what i have i don't think. i also planted these all correctly. my light is a hygger light i usually have it only the 24/7 mode with different color lighting.

thanks for any suggestions.
I think carbon might be your problem.

Most low demand plants like the ones you are keeping get their carbon from carbonate hardness. High demand plants will get their carbon from CO2, and due to their high needs it needs to be injected into the system. Low demand plants will melt as they use up the stored carbon, and new growth will be adapted to get their carbon from carbonate hardness in the water. In your case there is zero KH.

While it might say that excel is a CO2 source, it isnt. Its one of those products that doesnt do what it claims. It provides zero carbon. Its gluteraldhyde, which is more commonly used to sterilise medical equipment. Its toxic to fish, and even a small overdose will deplete oxygen to the extent that the fish will die. What it does do is act as a mild algaecide, helping to clean the leafs of algae and enabling the plants to better access the available carbon in the water. Given the limited benefits, and high risk, is it worth using this product in your aquarium? IMO excel and similar liquid CO2 products should be removed from the store shelves. Or at least they should be honest about what it is and what it does. I have used it to good effect when spot applied to clear up algae, and a deliberate overdose can clear BBA, but its risky and forums are littered with accounts of its use killing fish through O2 depletion.

Your pH is high, whereas your KH is zero. That doesnt really make sense as low KH usually causes pH to drop. I would get a 2nd opinion on your water parameters. Take a sample of water to the aquarium store and ask them for a full set of water parameters.

Your nitrate is very high too. If your nitrate is naturally high in the aquarium you dont really need Thrive. An all in one fertiliser that doesn't contain any nitrogen will suffice.
And just to clarify on the GH test. The drops are using degrees as the unit and the strips are using ppm as the unit. 17.8ppm to 1 degree. So your drops are reading as around 120ppm.

Remember that these are home test kits, not laboratory testing. They arent all that accurate. I would suggest the liquid test is more accurate, so your general hardness is in the moderately hard bracket.

Would be useful to have a similar set of test results for your tap water to compare against the results from your aquarium.
ok thanks u r the best, if its a carbon problem how do i get carbon? do i need to buy some sort of system that i see online? it seems very much like a pain to have... ive avoided even reading about them to much. ill bring in my water to sample for sure somewhere tommorow, i have kh drops but i dont think they work. i shake for 5 mins and water stays clear no matter how many drops i put in.

my nitrate is also high cause i messed up and over dosed plenty with thrive. i havn't put any in since, been slowly getting it down it used to be way way higher actually
Lets see what the second opinions are with your water parameters first, but raising KH might help and you can do this by adding carbonates/ bicarbonates. These can be introduced through adding an alkalinity buffer, or some form of calcium carbonate (crushed coral or cuttlefish bone) into your filtration, or baking soda, dolomite.

Plants tend to do better in harder water than softer water.

But as said, some of your parameters dont make all that much sense, so a 2nd opinion would be useful. With all the additives and fertiliser you are adding there shouldnt be a lack of nutrients, and the parameter that looks off is KH, so start there. Some plants dont react well to excel, but i dont think the plants you have are on that list. Valissneria for instance is known to die in the presence of excel.

You might want to look into an estimative index dosing routine for nutrients.
well i live in florida, tampa area to be exact so our water is very hard. so i took my water to lfs and first time getting water tested so i dunno how they are suppose to do it. they used the same drops i have at home api drops? and they only test for the basic ph/nitrate/ammonia/nitrite things so basically it didn't really help, again not sure if thats how they always do it. they don't measure gh or kh.

i told them what was going on they think its my lighting but its just a guess really. i have a hygger light that has all the color spectrum and it seems pretty solid but thats just me. i have about 15-20 fish in my tank so they say co2 shouldn't be a problem. you think i should experiment with a co2 diffuser thing? or is that different than carbonates/bicarbonates. i think im first just going to buy a co2 tester on amazon just to see

do u take donations or something i feel like u needa get paid for all this free info all the time lol
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All your plants are low light plants. They would probably do well with just the ambient room lighting.

If they can only test for what the standard test kit can do, they dont sound like a very good aquarium store. We are asking for a 2nd opinion because test kits have a tendancy to go off, people don't always do the testing correctly, even when they think they are. This is what i would expect a good store to be doing when they are doing a set of tests. Some might charge, some wont. Some will do a basic set of testing for free, and charge for a more comprehensive set. KH and alkalinity are kind of the same thing BTW.

If you are happy to trust your own testing though, the only thing that seems off is carbonate hardness, and the symptoms you describe are consistent with carbon deficiency.

If your aquarium store can't test for KH how about contacting your water company to find what is coming out of the tap. When people refer to hardness, they are usually referring to general hardness, so just because you live in a hard water area doesnt necessarily mean your water has high KH. Its KH you are reporting as low. Its normal for hardness to come from calcium carbonate, so if GH is high, then KH will normally also be high, but thats not always the case. The test above shows high GH but low KH for example.

I dont think an injected CO2 system will fix your problems. The plants you are trying to keep are all low demand plants. What you are trying to is find a balance between nutrients, light and carbon/ CO2. Overloading the environment with CO2 when you are trying to keep low demand plants is just going to fuel algae growth because the plants you have simply cant utilise the CO2.

Growing plants is often a trial and error thing. You could get a piece of cuttlefish bone and add it into your filtration. See if raising the KH a little improves things over a couple of months. Maybe lowering the light might help. It would slow down growth, but it might be healthier growth as there would be less demands for nutrients and carbon. Remember your plants are low demand, so they arent fast growing. Anything you do is going to takes weeks to show as positive or negative in your plants health. You need to change something, see what happens over a few weeks, then change something else. This way you can judge what has a positive effect and what has a negative effect.

As for payment the site used to have a subscription option, but it was discontinued a few months back. Site staff have always volunteered, the same as any other member who contributes their time. If people didnt want to contribute they wouldnt.
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OK I'll try the cuttlefish and I'll call around for a reliable water test, I did test co2 and it says it's low but since my plants are low demand, ur probably right I don't need extra, thanks for help
so just wanted to see what u think, i got my water tested at good place my kh immedatly changed colors so it means its very soft i belive, gh was 5-6 drops. i tested my tap water and both gh and kh are about 6-7 drops so somehow my tank is making the water soft?? hopefully i got that right. im not sure how.. i have a few plants, a terra cotta pot, some drift wood. some dragon stone. and the only thing that could be it is rock i got from my family shop, im not sure exactly what kind, some polished stone type i really just used them to weigh this driftwood down for a little while.. i read something good, gonna put these rocks in my extra empty tank and test and see if it changes also.
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Driftwood will lower KH a little, the nitrogen cycle will also lower KH. As far as im aware rocks can only harden water, but let us know how your experiment goes.

I wonder what effect the terracotta might have. Maybe add that into your experiment.

Your tap water is already soft so if you have a reasonable amount of driftwood, and quite a heavy stock of fish, along with an infrequent water change routine, that could explain where what little KH you have is going.

More frequent water changes might keep KH higher, otherwise the cuttlefish bone or crushed coral should raise is a keep it higher. Or an alkalinity buffer with your water changes.
just had a question last one in this thread, its pretty stupid, i was sold an alkalinity buffer which i was fine with, get it right there and be done with it. was just about to put it in its fritz rpm elements, in small letters it says for reef aquariums... so i can't use it in freshwater i assume? pretty stupid they would sell it to me if so...
I presume you got the part 1 alkalinity buffer? It says its sodium carbonate/ sodium bicarbonate so thats the same as other alkalinity buffers like seachem alkaline buffer. I cant find any reference to it being used in freshwater, and i don't know if it contains anything other than the carbonates/ bicarbonate.

Contact fritz?
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