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59 Posts
Discussion Starter · #1 ·
Hi All,

I set up a new ADA 30C cube (about 7 gallons) about a month ago and have been working through new tank issues, but seem to have some persistent melting on new and old growth on several plants in the tank. There is no livestock yet so I have been cranking CO2 and am doubtful that is the issue. I had what appeared to be a pretty bad rhizoclonium outbreak for the first few weeks which seems to be winding down everywhere except on my Monte Carlo, which has been struggling the entire time and looks pretty awful.

I'm having issues with black spots on stems of rotala H'ra as well as some dead spots on both newer and older leaves. Affected leaves will begin to detach from the stem and melt away, and most stems appear to be at least somewhat affected. The rotala still grows very quickly but the older growth will begin to deteriorate beginning with black spots on the stems. Old leaves of the Monte Carlo also quickly melt away and new growth is pretty small/slow. Some of the older leaves of my pogostemon helferi also have translucent patches or are falling off, but that plant is otherwise healthy. I've attached some pictures below.

The old growth deteriorating leads me to believe I have some sort of macro deficiency or imbalance, but with the Amazonia and Thrive+ dosing I don't see how that could be the case. Thrive+ at recommended dosage is already essentially EI dosing.

Lighting is a Fluval Plant Nano for ~6.5 hours between 50-70% intensity.

Water parameters are as follows:
- Tap water is soft, ~3 dGH and dKH, pH of 8.2.
- Tank is full of seiryu stone, which brings dGH up to ~10 and dKH up to ~8 the day before a weekly water change.
- Substrate is ADA Amazonia ver.2
- Dosing Thrive+ at recommended dose 3x per week (1.5mL per dose)
- Calcium from tap is ~20ppm, raises to ~60ppm the day before water change due to seiryu stone
- adding about 5ppm Mg per week via epsom salt during water change, calculated Mg to be about 9ppm before water change using GH/calcium test kits
- Drop checker is very yellow, and I am putting 2-3bps into a 7 gallon tank, haven't measured pH drop in a while but it is >1
- Nitrates read 10-20ppm per API kit, phosphate is somewhere between 0.25-1.0 ppm based on API kit

Any help figuring this out would be greatly appreciated!


36 Posts
That's amazing as I have an almost identical setup in a 3 month old ADA 30cm cube using Amazonia Ver2. Presently my plants are in 5cm deep pots (amazonia soil) but intend to remove all the pots and properly plant them using the same substrate soon. It was a bit of an experiment. All I can suggest is you use the same fertiliser routine I am doing - its been a great success. Only algae is some brown algae on the glass, a thin film. I have NEVER cleaned the glass! One day I am expecting to, but so far haven't needed to. I religiously do a 50% water change every Saturday morning. I stoppd the water changes for three weeks and the brown algae got worse. I have no fish in my tank only plants, but its full of what I think is Daphnia and other creatures. My water parameters are very similar to yours.

When I read your post I was surprised how similar your set up is. Not sure what your lighting is in Watts or lumens but I would suggest that could be part of the problem. Weak light promotes algae imo.

My setup is
A pre-mixed solution of 50% Seachem Flourish and 50% Seachem advance
2 mL/day (1mL/day if I only use the 7W GU10 LED spotlight)
Originally 1 bubble of CO2/5 seconds, but my CO2 system failed a month ago and now I just get slower growth.
Initially I had an infestation of detritus worms, but now I don't see them and they never did any harm. Maybe its an ADA Amazonia thing? Never noticed that before.

I NEVER CLEAN THE TANK - especially the detritus and plant mulm. It stays on the bare glass bottom and feeds the microorganisms/bacteria. During water changes I only remove water and rescue any large organisms and put them back in the tank. I occassionally add some fish food but haven't noticed any difference from that - there are no fish - its for the plants.

Bump: Plants are: (its a pretty crowded tank - 8 species)
Hair grass
Java moss
Christmas moss (on a small square stainless steel mesh)
US Fissidens (on a small square stainless steel mesh)
Lilaeopsis (brasil) grass
Cryptocoryne Wendtii Tropica
Monte Carlo-3 (the monte carlo is the only one not growing well - but its alive and not dying - just not growing as fast as the others- don't know why).

Initially light was 70W old metal halide (floor/reading lamp), 6 hrs a day, 1180 lumen
Then replaced it with a 20W DIY flood light, about the same lumen
Then replaced it with a 150W metal halide, same floor lamp (2870 lumen - yes its bright, I need sunglasses when looking at my tank)
Final set up is 150W metal halide (2870 lumen) plus a 7W GU10 LED spot light 2700K, but I have other bulbs at 4000K and 6500k (its very bright since it concentrates its beam at 35 degrees). Its on the lilaeopsis and hair grass and frankly would grow that grass on its own. The 150W is just extra. Since the 150W is not a spot light its not as efficient as the spot. The spot is awesome brightness for a 7W globe. Really impressive.

I suspect your lighting is too low, and fertiliser regime not as good as seachem. This seachem mix is like magic juice - plants are growing very well, no algae on them.

I have an eheim skimmer 350 that I only turn on once a say for ten minutes to clear the surface of scum and mix the fertiliser around a bit.

Tank temperature usually starts at 18 deg or 20 deg C early am, and the halide gets it to 25 deg C by end of the lighting period.

Bump: My Water
PH 8, GH 10, KH7, similar to yours

I could probably get away with half my lighting power, but the extra light makes my grasses grow better.

59 Posts
Discussion Starter · #3 ·
Thanks for the reply. My light is a 15W LED, generally considered to be high light for this size of tank since it seems to be about 100 PAR at ~12" which is about the distance to the substrate at the lowest point of the tank. If I'm running at 50-70% and the wattage is linear, then I'm probably at 7-12 watts. Not sure how the LED wattage compares to your light, but Fluval says it is 1000 lumens. Everything I have seen has indicated that adding more light generally causes more issues, and I have noticed that algae increases with more light. The plants also seem to grow better as well, but I'm not sure how sustainable it will be for me with the increase in aglae.

Up until last week I was doing 50% water changes 3x a week to clear excess organics during cycling. I was still having the melt issue so I don't think it was related to that.

I am also using regular Thrive, CO2, and Amazonia in my 29 gallon, with none of these issues observed in that tank. That tank has dragon stone instead of seiryu stone so the water is much softer, and the lighting is a 36" Fluval Plant 3.0 at ~80% for 7 hours.

I thought this could be something to do with potassium, phosphate, or magnesium. Phosphate seems unlikely since I am dosing like 1.3ppm 3x a week. I thought it could be something to do with the Ca:Mg ratio but I haven't seen anything about an imbalance causing this much of an issue. I also haven't seen much about potassium deficiency causing this much melting/rotting.

Bonus picture added of additional deterioration of new growth in the rotala.


36 Posts
Yes I am at the extreme end of lighting, no doubt about that. I estimate I am using 4-5x the light intensity of most people's aquariums. The tank I have right now is a bit of a mystery to me to be honest. I have never had a planted tank with zero filamentous green algae before but I have never used seachem ferts or ADA soil in the past. My previous experience was that the green stringy algae was a good thing - better than other algaes - and I took to be a sign that I have good water quality. I used to get that stringy green stuff all the time.

In this tank after 3 months all I get is brown diatom algae on the glass, but not dense enough to bother cleaning - I notice it comes and goes in terms of density. My lilaeopsis melted severely at first but is now growing well with new leaves.

All I can put it down to is seachem and ADA soil? Maybe daily fertiliser for plants rather than once or twice a week? Don't know. I have a tiny 2 litre tank with same plants in it, same ferts, ADA soil, and it has algae on the plants, but I thought that might be because I neglected to do water changes at first or the different lighting.

All I know is that my blinding lighting (I wasn't kidding about the sunglasses, I really do wear sunglasses when looking close up at my tank!) set up is producing good results with no discernable green algae or other algae on the plants or substrate. I have noticed that my water a few weeks ago either had a green-bloom or a bacteria-bloom. I think its bacteria as my tank now has a slight misty white /smoky look to the water. At first I was concerned, but it hasn't seemed to have harmed the tank at all, or the things swimming around in it. There are things in this tank swimming around that I don't know the names of.

This tank has made me re-assess my old ideas of lighting. FYI My lighting is 150W old type (probably about 40-50W LED). My 70W halide floor lamp is roughly equivalent to my other 20W LED flood light. The GU10 spotlight bulb is 7W, but I have 10W as well if I change the bulb. The GU10 bulb is simply fantastic. I am about to buy more of them. I don't use aquarium lights - I DIY or use general lamps over my aquariums.

Just thought you could try seachem and see if it makes a difference? I only use seachem since it works so well for me, but I do intend to try some others sometime, but not on this tank - this tank I am not touching as I don't want to interfere with it - its working too well.

I should point out that the water I use comes out of a river - I live rural - so the water has a green tinge to it, or bacterial?, not sure. Its untreated water for animals and domestic use (toilets etc..), not drinking water for people. But its stats, PH/GH/KH is the same as yours. Its got some sort of bloom going on, but my tank originally was crystal clear looking, with the same water supply. Its possible that as Summer is starting my source water is beginning to bloom more. Makes sense that in winter it would be cleaner. Might explain all the creatures swimming around in the tank.

My tank was doing quite well before at 20W LED intensity (old 70W floor lamp), I chose to increase it, so it would seem your lighting isn't the problem. Must be something else.
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