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No luck growing plants - why?

3313 Views 19 Replies 13 Participants Last post by  jonnythe, 
J
Hey everyone. I'm hoping to get some help as to why all the plants I've tried growing in my 36 gal low tech just don't do well. It had been running for a couple of years with no artificial lighting and a very low bio-load, until several months ago when I set up the lights to have a go at a community planted on a budget.

The tank has plain washed river sand as substrate, 2 W/gal of lighting. 6500K full-spectrum bulbs. Never CO2.

At first I had some limnophila (ambulia) which just melted away and the small amount of growth was pale and yellow. Giant vals wasted away with only a couple putting out new leaves, but they were small and brittle. Anacharis has grown good sometimes and poorly other times. Right now the growth is spindly and much of it is yellow. There's also some giant hygrophila which I think likes high light, so the fact it has pale and distorted growth may not really tell whats going on in the tank.

When I asked about these problems a while ago, first people said it looks like iron deficiency. So I got hold of a trace mix which has iron and now iron levels are 0.3ppm if the test kit is accurate.

I also thought it could be calcium deficiency. But due to our water being very soft I'd mixed in a small amount of crushed shell to the substrate as a buffer. This has kept the pH at around 7.4, GH and KH both around 6 with the 15% weekly water changes.

Others have said it's probably not enough light. But a friend took my leftover river sand and set up a 2-foot tank with less than 2 W/gal lighting and all the plants I've tried grow fine in his tank. And he doesn't add anything to the tank. This made me think there maybe too much light for the setup, but I tried reducing the intensity for a while with no apparent effects.

Water parameters seem fine: Ammonia 0ppm, Nitrite 0, Nitrate 10-15ppm, others as mentioned.

Now, it may be a light problem. Upgrading that isn't an option right now. So if it's not the lights, what else could I look at? Some thoughts running through my mind (probably all silly) are:
-Ca:Mg ratio out of whack causing nutrient lockout.
-Substrate pH too high from the crushed shell, also preventing nutrient uptake (think vals should like high pH though).
-Other nutrients at too high levels, due to accumulation from poor plant growth.
-Substrate becoming toxic in the time before plants were added.

Do any of these make sense? I did some big water changes a while ago in case it was nutrient build-up, but it never helped. Most plants I've uprooted have what seem to be healthy root systems. And I doubt it could be metal toxicity as I had some shrimp in there for a while and they all lived fine.

Anything else I should think about before giving the plant idea the flick? I'm not looking for the 1 foot of val growth per week I had in my old 54 litre. Just green plants!
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yoink
Are you adding any fertilizer, nitrogen, phosphourus, potassium, and a trace such as seachem's flourish or tropica plant nutrition. Rex's guide has some good info regarding fertilizing as well as other aspects of a planted tank.
http://rexgrigg.com/ferts.htm
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P
what is the temp of your tank?

i'm not sure what's going on....the hardness you've added should be fine, i have a tank with coral, ph 8 and plants grow crazy

is switching out the substrate an option?

kara
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CrazyMidwesterner
I have no idea what it is but I can tell you what it isn't.

It is not your PH, or overdosed nutrients. Many people who use EI overdose, some accidentally by gross amounts :eek: (me at first) and have had some good plant growth.

You said you had 2 watts per gallon, but what kind of lights? NO fluorescents, PC, incandescent? That may be a factor but I can't say for sure. Are you getting water from your tap? If so is there a water softner attached? Just throwing punches in the dark now :)

Give this a read. It's worked well for me http://www.barrreport.com/articles/433-non-co2-methods.html
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V
"The tank has plain washed river sand as substrate, 2 W/gal of lighting. 6500K full-spectrum bulbs. Never CO2." IMHO I think you need some thing more than plain sand. The substrate is the most important and basic fundamental for plant to grow. You can try mix the sand with nutrient rich substrate (soil, eco-complete, fluolite) or use fert tab.
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J
Thanks for the replies everyone.

I do realise that low tech tanks seem to benefit from an "active" substrate such as added soil etc. However many people grow great plants in straight sand. And there's a good buildup of mulm in there. I was planning on getting some red clay from the river here, mixing with some soil and sliding under the sand to see if that would help (freezing or drying it first). I'm kicking myself for not coming across Walstad's book before setting up the tank. But even plants that were left floating seemed to have problems growing. I've had thoughts of switching the substrate to pool filter sand as it's pretty much guaranteed to be almost pure silica. But the river sand wasn't a problem in my old tank, or my friends.

As for the lights, they are NO fluoros. I thought the old bulbs may not be good enough and replaced them a few weeks ago with the better ones. It's DIY lighting and the fixtures have pretty good aluminized reflectors in them. It looks a fair bit brighter than my friend's successful tank even at substrate level.

Ferts: I was dosing a macro mix up until a couple of months ago, when I thought that could be the problem. If I could get the plants to at least grow with that stuff my plan was to get some pure macros. But I'm not wasting money on them until some success comes my way. And I expected the fish load in there now would take care of most with the amount of light. At one time it was suggested low potassium might be causing problems, but dosing K2SO4 didn't help either. And I'm pretty sure excess nutrients can cause problems with uptake of others in some circumstances.

Also, I haven't got a phosphate test kit. I'm a little scared to dose that since I haven't a clue if it is deficient or maybe excess. IIRC, excess phosphorus may lead indirectly to Fe or Zn deficiency. Maybe that is the problem?

So my options seem to be:
1. Pull tank down, start from scratch with better substrate
2. Begin EI dosing and hope for the best.
3. Let the tank have a rest, water changes only for a while to see if it gets better. Also give the substrate a good clean out.
4. Swap the tank for my friend's ;)
4. Forget about plants :(

Any other thoughts/ideas?
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H
jonnythe said:
Thanks for the replies everyone.

I do realise that low tech tanks seem to benefit from an "active" substrate such as added soil etc. However many people grow great plants in straight sand. And there's a good buildup of mulm in there. I was planning on getting some red clay from the river here, mixing with some soil and sliding under the sand to see if that would help (freezing or drying it first). I'm kicking myself for not coming across Walstad's book before setting up the tank. But even plants that were left floating seemed to have problems growing. I've had thoughts of switching the substrate to pool filter sand as it's pretty much guaranteed to be almost pure silica. But the river sand wasn't a problem in my old tank, or my friends.

As for the lights, they are NO fluoros. I thought the old bulbs may not be good enough and replaced them a few weeks ago with the better ones. It's DIY lighting and the fixtures have pretty good aluminized reflectors in them. It looks a fair bit brighter than my friend's successful tank even at substrate level.

Ferts: I was dosing a macro mix up until a couple of months ago, when I thought that could be the problem. If I could get the plants to at least grow with that stuff my plan was to get some pure macros. But I'm not wasting money on them until some success comes my way. And I expected the fish load in there now would take care of most with the amount of light. At one time it was suggested low potassium might be causing problems, but dosing K2SO4 didn't help either. And I'm pretty sure excess nutrients can cause problems with uptake of others in some circumstances.

Also, I haven't got a phosphate test kit. I'm a little scared to dose that since I haven't a clue if it is deficient or maybe excess. IIRC, excess phosphorus may lead indirectly to Fe or Zn deficiency. Maybe that is the problem?

So my options seem to be:
1. Pull tank down, start from scratch with better substrate
2. Begin EI dosing and hope for the best.
3. Let the tank have a rest, water changes only for a while to see if it gets better. Also give the substrate a good clean out.
4. Swap the tank for my friend's ;)
4. Forget about plants :(

Any other thoughts/ideas?
Click to expand...

It seems to me that you have pretty much thrown everything but the kitchen sink at this problem. If I were in your shoes, I would go with option 1 - pull tank down, start from scartch with better substrate. I believe that your substrate may be at the root of your problem.

If you are looking at a good low tech/low maintenance set up, I would setup as per concepts in Diana Walstad's Ecology of the Planted Aquarium or try a set up based on the recommendations here.
http://www.malloftheworld.com/aquarium/part1.htm

Both are cheap alternatives and won't cause you to sink a fortune in a new setup.
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dobie832
You need to test PO4 and K. PO4 ~ 0.5ppm; K ~25ppm. N sounds good; iron is a bit too high. You need to see what the spectral output of your lights are putting out. Just because 6500K doesnt mean that it is good light for plants.
What type are they?
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macclellan
jonnythe said:
So my options seem to be:
1. Pull tank down, start from scratch with better substrate
2. Begin EI dosing and hope for the best.
3. Let the tank have a rest, water changes only for a while to see if it gets better. Also give the substrate a good clean out.
4. Forget about plants.
Click to expand...
3. Sounds like what you are doing...no dosing. So that is more of the same. That is, more of what isn't working.
I'd suggest trying 2. before trying 1. That is, try dosing some nutrients so limited nutrients aren't a worry. If, after 4 weeks or so of that not working, then go to option 1.

You say you have a 'very low bioload.' So, why would you think that fish poo etc alone is giving enough nutrients? My guess is that it isn't.
For example, I have 36w AHS Supply light on a 20g (so, about 2 'good' wpg), and I have to dose macros regularly, especially N, despite having a pretty high fish load (3 catfish, 4 butterfly cichlids, and 6 tetras) and only a 6 hour photoperiod. I have a flourite substrate with lots of mulm, but that isn't enough, it ain't like it is soil. Plants are growing as fast and nice as I imagine they can without adding co2.
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J
Homer, yes I borrowed Diana's book last year. Though I didn't get to read all of it.

macclellan, I said before converting to a planted tank it had a low bioload. Now it's a community: cats, corys, gouramis etc. The fish are very healthy and that's why I now think there's not a huge problem - I'm just starving the plants somehow.

And I feel a little foolish now. For some reason it was stuck in my head that the accumulated mulm from several years would give many benefits of soil. I remember several people saying this to others who were considering converting to NP tanks. But I now know this isn't "general consensus". Soil is also important as a carbon source with a non-injected tank and mulm just doesn't cut it in that respect either.

So, do you think I should tear everything down, or would it be worth trying something like this? If Tom Barr says it works then I'm prepared to believe in it. But has anyone tried and found it more hassle than starting from scratch? I was thinking if I add the soil/clay slowly the tank will keep more stable compared to a complete tear-down.
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T
What is your filtration system? Surface agitation etc???
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J
TalukderE, I used to have a sump but removed it when adding plants. At the moment I'm running a HOB just for polishing and circulation. I've been thinking whether this is part of the problem. The water level is kept lower than the waterfall of the HOB for several reasons. So I made a "ramp" which diverts the flow across the water surface so it doesn't splash. People have always told me surface movement is ok but splashing is what outgasses CO2. Maybe this is a problem in my tank though?

Anyway, some of the elodea has started to get some color back in the new growth. I potted one of the healthier hygros in a container of soil. It's probably too early to notice any changes yet, but it hasn't started growing any better.

I really have no idea with this tank. I'm about to spend a couple of hundred dollars on proper lights (and more watts), but I really don't think it's going to help. And I'm seriously considering trying a soil substrate, NP style tank.

One other thing I didn't mention, although I've kept shrimp in this tank, apple snails and freshwater mussels don't seem to live long. That's why I thought it may be heavy metal poisoning or something. But the native shrimp I had are sensitive to this as well and they were in there for months.
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bulrush
Hi,
One thing I did not see answered is: Do you have a water softener and do you get tank water from this tap? Water softeners add a significant amount of salt to the water when they backwash. I am not an expert on aquatic plants but I do know terrestrial plants do NOT like salt at all.

Also, I have a cheap plant setup. I'm growing plants in tanks containing shrimp, fish. I have 7 tanks, all with java moss and various types of lights. Java moss grows great and I do not fertilize at all.

On one tank (I call #2) I do have an 18 inch flourescant bulb designed for aquarium plants. It is on 12-14 hours per day, I don't remember how long exactly. Cabomba and java moss grows well. Some cabomba is rooted into the sand substrate. Some is floating and has long healthy roots.

On another tank I have a 70w equivalent CFL in a cheap shop fixture, you know, the metal funnel shaped one. Java moss and guppy grass grows just fine there, just floating around.

If anyone is doing a budget lighting scheme it would be me. $4 CFL plus a $6 metal funnel fixture. How cheap can you get?

Last year I used a screw in halogen bulb. It goes right into a regular socket. It was nice and bright but used a lot of power so I switched it to a CFL.

All my lights are on 12 hour timers. It seems the plants need at least 12 hours of bright light per day. But then again the plants I chose are low light plants.
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J
No, there's no water softener here. There's no need for one since tap-water is already very soft.

I can't believe even hornwort isn't doing well now. In my 2gal shrimp/snail tank it's beautiful and green and fills the tank, along with the java moss which is totally lush and clean. Never done a water change in it. Substrate consists of a thin layer of shrimp and snail poo. Only thing added is a pinch of fish food a week and a bit of carrot every now and then. Lighting is whatever reaches the tank from my 11W CFL desklamp, photoperiod is controlled by when I decide to wake up and when I decide to go to sleep.

Going by this and all the things I've tried, it seems there may be no choice but to do a full tank overhaul. Or do you think if I take fish and everything out of the tank, stir up the gravel repeatedly for the day with the HOB flat out, then do a 100% water change, there'd still be enough bacteria and mulm to only have to go through a mini-cycle?
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T
Hi, It is hard to say what is going on in your tank. Do you get a lot of algae? I also had a similar situation as yours. I could not grow any pants in my 55G tank. My tap water is very soft and I added crushed coral to keep the ph stable. I had canister filter without any surface movement. The tank will always had all kinds of algae and would kill plants. Finally I tear down my tank. I found out that our tap water had phosphate added to it. So, this is what I did:
1. Tear down my tank removed all gravel. Filled up with tap water with a 1/2G bleach. Kept the bleach water for one day. Next day I pumped all water out. Washed it with new water and dechlorinated it. Then left it for a day to completely dry out.
2. I used kitty-litter (1 inch), pool filter sand (1.5 inch) and a thin layer of pea gravel.
3. One of the local fish store was kind enough to give me 20G RO water. I brought the water home and mixed CaCl2, MgSo4, Backing Soda in appropriate proportions.
4. I planted the tank (moderate to heavy)
5. Put the 20G water. It did not fill my tank(!!) but cover all the plants.
6. I had 2 40W fluro bulbs and I did not use any filter or any ferts
7. A week later, the LFS was kind enough to sell another 20G RO water. And again I got another 20G ro water from him. This time my tank was completely filled.
8. I did not use any filter or pumps for 2 weeks.
9. After one week, I brought my 2 rainbowfish from the holding tank. They were fine for one week before I brought 4 ram from the holding tank. All the fish are doing very good. The tank is up and running for more than 2 months. No algae. I have added a very small powerhead for water movement. I have not added the heater yet as the weather is still warm but will be adding it this weekend. I feed 2 times a week. Water is clean, plants are growing. No algae. No CO2, no fertilizer yet. I will not be changing water that frequently. I am thinking to change 10 to 20% water every three months.

I provided all the above in case it helps.

all the best,
Enayet
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J
Just a bit of an update. I ripped all the plants out and have given the substrate a good mixing up to clean it. The Elodea is putting out green shoots again so I think giving the tank a rest has helped. The hygro is getting green again as well. Especially the one potted in soil. Got some better ferts but they are phosphate free. Until I can get a P test kit I'm not going to dose them though.

I now have around 2.5W/gal of light with a mix of tubes. And bought some new plants. The substrate is only a little above an inch thick now that I've leveled it out evenly. I am going to buy some pool filter sand to mix in with it to make it 2" deep. One question though, when I was mixing the sand up with my hand, certain parts gave a sort of greasy feeling on my skin. I've never felt it before and was wondering if this is a sign of aerobic conditions? Like I said there's no gases or smells coming up but I'd just like to make sure.
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plantbrain
Jonnythe,

Are you doing water changes?
Low tech is suppose to be, well....low tech, no testing or messing with all this stuff.

Watch plants, add ferts when needed etc.

Good algae eating crew, good plant density, lots of easy to grow weeds.
And no water changes.

EI is not appropriate here.
Some ferts later as the tank ages might be needed, or some GH booster.
PO4 is not going cause any issues if you add it, but your sediment ought to have a fair amount still.

If you seek balance etc, then you'll need to focus on no water changes, more fish, perhaps a little dosing once a week or GH booster (K+, Ca, Mg, SO4, Fe, Mn) at 1/4 teaspoon per 40 gallons or so.

Make sure you have a good washed soil, soak it for 2-3 weeks in shallow tray with water, or boil it 10 min, or bake it for 1 hour at 400F etc.

Add zeolite to any new tank's filter.
Pack the tank with plants.

And no water changes, no testing etc.

You already know what plants need to grow well :hihi:

Regards,
Tom Barr
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A
Do you use any kind of Treated Water or Medicine for the water? Maybe it's doing something to the plants. I hope you find out why your plants aren't growing soon! :icon_smil
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frozenbarb
Im still thinking its a light problem, and im Concern about the light..

What kind of light is it. How much watt is it.. its jus tubes? Do they Cover your whole tank?

Because i used to add alot of light fixtures to my tank.

like 15W on the left 20W cover the whole tank another 15W on the left. and a 26W on the right Total 76W over a 30 meaning 2wpg.. And i dont think this really counts are 2Wpg
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J
I don't use any medications/treatments, apart from ACE for change water.

Anyway things seem to be coming good, fingers crossed.

I added some new ambulia and it's putting out healthy shoots everywhere. The tops are turning red. When I put some in the tank all those months ago it just melted away. Some of the elodea is getting very dark green growth. Never seen it that green before.

The lights are 2, low profile fluoro fixtures I found at a local lighting shop. I have replaced one of them with a proper aquarium fixture. I don't know how much that is helping yet. However there's an extra 0.5W/gal now. I gave the fluoro fixture to my friend for his tank. His plants now pearl sometimes, so I doubt the spectrum is bad for plants.

So I hope everything keeps improving. If it does then I really don't know what was wrong.
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