The more light that you have then the greater the plants requirement is for food, the addition of CO2 helps the plant take up the food that is required faster and more efficiently.
i would say that your medium-high light levels plus the long photoperiod and addition of CO2 is causing your plant to eat up the available nutrients and ultimately starve itself of particular nutrient(s) when the supply is exhausted.
My Puffers: Puffers I have kept: T lineatus T miurus A modestus T biocellatus C valentini C coranata C papuan C lorteti DPs suvattii burrfish T niphobles
OK, first off, clarifications: 2x30W = 60W over 50US gallons, or 1.2WPG US. If the lights are normal output, T12 or T8 (1.5 or 1.0 inch diameter) , then you have low light. Echinodorus, swordplants, will take low light but grow very slowly. They are gross feeders. Your light interval is not long for such low light intensity at all. I use 12 hours routinely at higher intensities that you are using - for a 50 I would use at least another tube of that same size and wattage. With CO2 supplement, I would likely add a 4th tube. Both of those situations would get some added fertilizerss or supplements, especially with CO2.
Do you know how much CO2 you have in the tank?
How long have you had the plant in question? Was it emerse grown (Tropica or other similar commercial plant source, or was it from another hobbyist"s tank (submerse grown)?
Do you have a test for KH, alkalinity, or carbonate hardness (all are KH)? If so, what is the scale based on? CaCO3 or CaO? and what reading do you get?
What is the scale basis of your GH test? 31 what?
Why add CO2 with no fertilizers added?
What is the tank temperature?
Is there current in the tank which can be seen?
How do you handle the drop to the sump and return to the tank?
I the meantime, I agree that it looks like a deficiency, but it also could be simple submersion death if the plant was formerly grown emerse. The new growth would not show such sypmptoms, and would continue symptom-free indefinitely.
It could also be simple physical damage if the plant was moved fro one hobbyist to another.
Thanks for your reply, the answer to your questions:
- I don't know how much dissolved CO2 I have in the tank. I am using a CO2 drop checker and the color is light blue which would be intepreted as low or insufficient CO2. If you count in bubbles/second then I got 4-5. The CO2 goes into sump where I have a CO2 diffuser inside an empty mid filter. Here the water is mixed with CO2 and pushed via a hose to a Tetra outflow kit pipes. The intake is a white large PVC tube as seen in photos. I measured how much water goes from the sump in 1 minute and calculated the total flow of about 600 liters per hour (or 158 US gal). This is about 3 times tank volume.
- I have the plant for about 2 months by now, it was small, maybe 3-4 inches height. All leaves were fine.
- I don't have any KH test
- GH of 31 dH german degree hardness
- I supply CO2 to tank to stimulate plant grown
- 24 degrees Celsius = 75.2 degrees Fahrenheit
- There is a slow water movement at the surface and due outflow kit I believe it's similar in all tank areas (because it's a drilled tube from top to bottom)
- Water goes over a pipe from tank to sump and pushed from sump back to tank by using an empty filter which instead of filters material got a CO2 diffuser.
It's worth to mention that a new leaf shows the same symptome after reached the water surface. All new leaves that are submerged looks fine. Also the plant is flowering right now.
Thanks for your time and help, looking forward for your reply.
Standpipes blow off CO2 massively, but without more light and routine fertilizers your CO2 efforts are wasted in any case. Air-contact diffusion should provide more than enough CO2 for such low lighting levels.
Your water by the German scale would be 310 ppm CaO, which is massively hard. If your KH were comparable, the pH should be much higher, not at neutral.
The air-contact bit introduces another variable or two actually. If the other leaves were in a shallower tank and had air contact, they could have been dessicated and injured by that - browning is characteristic there, and/or burned by the lights - for the same appearance.
But you do really need a KH test kit.
For planted tanks, you nitrate is quite high. What is the nitrate and phosphate level and pH in your tap water - or whatever water source you use for the tank?
How often do you do partial water changes, and what percentage of the total system volume is changed each time?
In any case, you are not shy of nitrate, but it is out of balance with phosphate. the N:P ratio should be about 7-10:1::N:P. Plants cannot grow with that ratio significantly out of balance. Don't bother making corrections until we have more information.
Has the pH of the tank declined in the period since it has been set and planted?
I got KH (carbonate hardnessy) and Fe test and did a full test fresh water vs aquarium water after yesterdays 40% water change which is performed weekly. I use freshwater for tank which comes directly from ground via some commercial filters. Here are the results, (aquarium tests performed at the end of 12 hours of light and CO2 injection, both tank and freshwater tested at same temperature of 24C / 75F):
Freshwater *** Aquarium
pH 8 *** 7-7.5
GH 32 *** 32 dH (degrees of German hardness)
KH 32 *** 32 dH (degrees of German hardness)
NO2 0 *** 0 (mg/l)
NO3 15 *** 15 (mg/l)
PO4 0-0.5 *** 0 (mg/l)
Fe 0-0.05 *** 0-0.05 (mg/l )
Water change performed every 7 days; 35-40% of total volume.
The pH of the tank was always between 7-7.5 with CO2 injection.
I removed all the leaves that show any sign of damage; besides healthy mature leaves there are new small leaves at the base.
I have JBL Ferropol that I can use (I never did so far).
Changed light from 2 x 760 30W to 1 x Osram 830 plus 1 x Osram Fluora 77.
Before: 2 x 30W Narva LT 30W/760 (daylight 760) 1950 lumens; Total 60W / 3900 lumen
Now: 1 x 30W Osram Fluora 30W/77 1000 lumen + 1 x 30W Osram 830 2400 lumen (warm white); Total 60W / 3400 lumen
Could you please elaborate a bit on the lumen vs wattage because it seems there are some theories about it.
If the tubes are trihosphor (that is, are made with three different phosphors to cover the broadest spectrum) and have a color temperature around 6500K, they will work. Different brands have different "looks" (color rendering to human eyes), and folks do have strong individual preferences, but plants do not use light as we see it. Lumens are a measure of brightness as seen by the human eye.therefore worthless as a plant measure. If you go for high lumens, you might as well by cool white tubes they are the cheapest by a wide margin and you will use much more power (wattage half again to twice better balanced tubes will be needed, driving power costs way up). Unfortunately the plants will look really awful and so will the fish. "Broad-spectrum" or "Full Spectrum" tubes are more likely to please both the human viewer and the plants, with individual preferences on the particular tubes used from within those categories. A color temperature of ~6500 Kelvin (or K) is about right for FW. SW, especially with inverts, needs a higher color temp.
But regardless of the spectrum, you still have low light (~1.2 Watts per US gallon) and you will not have lush plant growth. You can still have a nicely planted tank with very careful selection of plants and time to allow them to slowly mature. If you like the appearance of the current lighting, keep it. Try to find some Vallisneria spiralis - a grassy plant for background growth. It will grow slowly but should survive. Ditto for Anubias barteri var. nana. It is fairly expensive because it is slow-growing, but it is all but indestructible, Trim the roots a bit and plant in the substrate, with the rhizome horizontal with the substrate and at least 1/4 to better 1/2" above the substarte, only the roots buried. It will grow slowly into as full a carpet as you want. In between, plant several Cryptocoryne wendtii cultivars - pick color forms that you like, it comes in multiple colors and forms, mix or match as you wish. Th Val will need thinning and replanting every year to year and a half, the Crypts about the same interval. The A.nan only needs thinning if it is getting too thick or growing where you don't want it - then cut off the rhizome and move the unwanted section somewhere else after trimming the roots back a bit. After removing plants when thinning, always substrate vacuum full depth and replant part of the plants, using the others elsewhere. Once reasonably fully planted, only lightly surface vacuum without disturbing the plants other than when thinning and replanting.
You will have better results if you boost your partials to 50% weekly. You would like the nitrate level about 10ppm or mg/l post partial, never more than 15 ppm. You may need to add iron periodically is the plants look pale or yellowish.
Don't try the stem plants (you have some now) -you do not have the light they need. The Swordplant may adapt and grow slowly, or may fail. You really don't have the light it needs, but i have seen swords grown very slowly in quite low light.
The above setup will grow for years with no added fertilizers or supplements, but will grow a bit better if you have access to Serachem's Flourish Excel, and add it at standard dosage about every other day.
I would suggest changing one tube every six months to keep the tubes in their highest output. that way all the tubes will be used for a year, but with staggered start time on that year of use.
If I were you I would still try dosing a fertiliser that contains phosphate and potassium as well as trace elements and see if they perk up, the CO2 that you add will help the plant take up the ferts more efficiently and may compensate a bit for your low light levels, but as RTR says your lighting is really set-up for a low tech tank with slow growers.
RTR: you appear to mention weekly 50% water changes with a low tech set-up, I've always read that with a low tech tank you would limit nutrients and perform less water changes in order to keep the CO2 in the tank more constant and in so doing reduce the amount of algae?
