Why do I keep killing easy plants?

[rubadudbdub]

Hi guys. I have a recurring problem with my tank which is that I keep killing plants which are supposed to be easy. Hygrophilia polysperma, amazon swords, bacopa, Vallis, hydrocotyle leucosomethingorother, limnophila sessiflora etc, all have suffered the same fate. Most seem to struggle, with small leaves or holes in the leaves and become leggy. The bottoms rot away then they float at the top until I throw them away. Occasionally they do well then wilt away, nymphoides did brilliantly for six months then died, currently the limnophila is dying back after good initial growth. Sometimes they do better once floating at the top and throw off some healthier looking leaves.

In a previous thread I had problems with blue green slime algae and cut down light, bought floating plants and tried co2 for a while. All this helped and the plant growth was definitely better with co2. But I regrettably struggled to keep up with weekly large water changes with busy job and young family so tried to switch to low tech.

I thought that cutting light and increasing flow I'd find the point at which the plants would stop melting but I'm still struggling. The tank is juwel rio 125, with two 18w t8s one 865 daylight, one grolux (both cheap lampspec bulbs about 18m to 2 years old), on for four hours in the late afternoon, off an hour, back on for three hours in the evening. Reflectors have been removed, very little sunlight hits the tank. I dose TNC complete 1-2 times a week, which I think is overkill but intended to avoid nutrient deficiencies. There's an eheim stream pump to improve flow. Water changes once every three to four weeks if I'm honest. I know it should be more often. Substrate is mostly just gravel. There are some areas with tetra substrate under the gravel.

I'm not after a show winner tank, just a low tech tank with something other than java fern. The melting plants and dusky algae on the java fern makes me think there's still too much light for the amount of co2. Should I cut the photoperiod more or am I missing something? Is TNC complete enough or should I add other nutrients?

 

[Keith GH]

rubadudbdub,

I thought that cutting light and increasing flow I'd find the point at which the plants would stop melting but I'm still struggling. The tank is juwel rio 125, with two 18w t8s one 865 daylight, one grolux (both cheap lampspec bulbs about 18m to 2 years old), on for four hours in the late afternoon, off an hour, back on for three hours in the evening. Reflectors have been removed, very little sunlight hits the tank. I dose TNC complete 1-2 times a week, which I think is overkill but intended to avoid nutrient deficiencies. There's an eheim stream pump to improve flow. Water changes once every three to four weeks if I'm honest. I know it should be more often. Substrate is mostly just gravel. There are some areas with tetra substrate under the gravel.

I think all your concerns are listed here.
with two 18w t8s one 865 daylight, one grolux (both cheap lampspec bulbs about 18m to 2 years old),
Old and cheap, buy new quality units

Reflectors have been removed,
Why?

very little sunlight hits the tank.
No direct sunlight should be on tank at all (it can cause Algae)

TNC complete 1-2 times a week, which I think is overkill but intended to avoid nutrient deficiencies
Dose can be increased to 2 or 3 times per week depending on plant growth, water changes etc.
Are you using it strictly to instructions.

Water changes once every three to four weeks if I'm honest. I know it should be more often.
That is a massive under statement at least 2x35% twice a week for a healthy tank.

Looking at those photos you certainly have a plant deficiency problem.

No mention of "Filtration" what are you using "Info please"
How is cleaned and how often?
Filter medium type?
Do you have any Carbon in the filter?

This will help to help you and your plants.

Keith

 

[Edvet]

This might be one of the few times there might be a situation with low light. T8's do degrade over time, 2 years is long. I think 2 new T8's , any color will do, get cheap ones, and start with a 6 hour period. I wouldn't add reflectors yet. Improve cleaning maintenance, try to do 50% once a week. Ferts 2 times a week and then give it a few weeks to see what happens.

 

[ian_m]

1. Might want to consider replacing your T8 tubes. In my experience T8, unlike T5's, do reduce in light output after a year or two.
2. Try 6 hours, with no reflectors.
3. TNC does not contain any carbon or potassium or magnesium or macro nutrients source for your plants, no wonder they have issues. You may be able to get away with TNC lite (contains your missing potassium, magnesium and trace elements) and rely on nitrogen and phosphates (and carbon) from fish poo and fish food (instead of TNC complete), especially if lower light.
4. If low light and low tech then water changes every couple of weeks will be fine.

So initially consider using TNC lite (as well), try dosing the recommended amount, increasing to say 2 - 3 times, spread out during the week and maybe even consider some liquid carbon (TNC liquid carbon).

You find the TNC products expensive, as you are really just buying water consider dosing dry salt of EI method. The starter kit from www.aquariumplantfood.co.uk will last years on low light tank. Just dose say 1/5 (or less) amount. My mate runs a low tech tank, single T5 tube dosing the EI salts once a week (if he remembers), water changes...when ever...and his plants do grow slowly and algae free.

 

[Maple]

I had somewhat of a similar experience recently. My tank was running over a year with healthy plants growth and minor algae issues, and then easy plants started dying or stopped growing. Hygrophilia Corymbosa compact died, crypts developed holes in leaves, echinodurus rose nearly died, and some of the plants bottoms were rotting. I doubled my nutrients dosing as my floaters were also struggling. After couple of weeks, plants started growing again. In my case it was the lack of nutrients that was causing the damage because I was sure, since I have a low tech tank, that I am dosing more than enough.

I am doing a weekly 30-50% water changes because I think my tank is a bit overstocked with fish so I am sticking to it for their health, but with a low tech tank you can get away with less regular water changes. Anyone following some form of Diana Walstad method wouldn't dream of doing big weekly water changes. You have to find best way to run tanks for your lifestyle. It doesn't look like you have a problem with water changes, but with possibly not enough light or nutrients. Once you have too much light or you are overfeeding your fish, you will have problem with water changes, because after two weeks with no water change you will notice your tank growing algae as successfully as plants. Water changes curb that problem.

The deal with low tech tanks is, you are supposed to achieve a balanced tank with just enough light to grow easy plants, not much algae, and less maintenance.

 

[Maple]

3. TNC does not contain any carbon or potassium or magnesium or macro nutrients source for your plants, no wonder they have issues.

TNC blurb: 'TNC Complete contains a balanced blend of Nitrogen, Phosphorous and Potassium as well as Magnesium and all the important trace elements.'

Never used it but I think he is dosing the right stuff. But I agree with EI dry salts being much better option.

 

[techfool]

I don't want to make it sound like the magic bullet but increasing ferts and liquid carbon has helped all four of my little tanks. Including the one in direct sun (which did have an astonishing amount of algae at first). In that one the pennywort and hygro has breached the surface and looking fantastic, as is the frogbit.
As it's easy to do, I would try that.