Unhealthy Looking Plants

Hi,

Below are the plants I have in my aquarium, They all have a "brown" colouration to the leaves and some with holes in the leaves with some "yellowing". I presume that the "brown" colour is a consequence of algae (diatoms)? The plants are planted in Tetra Complete with a fine gravel topping, I have been feeding with "Flora Grow" and using liquid Co2. The plants do show signs of "new green growth" but very soon turn to the "brown" colour? What am I doing wrong. The aquarium is approximately 4 months old, fully cycled. Water parameters show 0 ammo, 0 nitrite, 0 - 5 nitrate (difficult to determine) and phosphate at 0.25 - 1ppm.

Bacopa amplexicaulis (Giant bacopa)
Cryptocoryne wendtii green
Echinodorus grisebachii Tropica
Hygrophila guanensis
Hygrophila mini
Staurogyne repens 

Matt,

Substrate is about 3 - 4cm and the gravel topping about the same. I have 4 Amano shrimp and one Nerite Snail.

The reason I say that determining the nitrate level is difficult, is because the resultant colour of the API Master Test shows a "yellow colour" the same / similar to the colour chart indicating no or very little nitrate! I have thought about getting a couple of Oto's but did not want to add more fish to the aquarium at this time.

Sue,

I shook both bottles for well over a minute, I even stirred bottle #2 with a clean stainless steel rod to make sure it was fully mixed. I have not added any further fertilizer, just liquid Co2. I will be doing 30% water change Saturday to which I shall start to add Seachem Flourish at the recommended dosage to see if things improve. Would root tabs be of any benefit as well? As I said previously, new growth is evident but the new leaves very soon turn a "brown colour"? I forgot to mention that I have also had / got what I presume to be "green hair algae" only on the rear of the aquarium glass, if left to grow it appears to "wave" in the water movement?

Sue,

Local water report (Oxfordshire) indicates 50ppm, when I test the tap water the colour of the test is "dark red" indicating that the level is well above 50ppm, but at least it shows my test kit is measuring something. There is a lot discussion elsewhere on other forums as to the accuracy of the API and indeed other nitrate test kits but, in the absence of anything else other than "laboratory equipment" what else is there? As I said, when the tank water is checked it is "yellow" indicating zero or very little nitrate? I too would like to know how / what to add to the water to at least see a change of colour to the test to indicate at least a possible 10 - 20ppm of nitrate.

Sue,

Because I have what I think is a high nitrate level in the tap water I have a Nitrate filter for it which I mix with RO/DI water at around 30% (3lts Ro / 7lts filtered tap) and relied on the "fish waste" etc to give the nitrates? I would say that the tank is moderately planted (approx. 110lts actual water volume). Do you think I could slowly introduce unfiltered tap water to the RO/DI water at the same ratio or maybe 50/50?

Hi Baz,

How long do you have your lights on? Algae might also suggest too long a lighting period.

8 hours should be ok now. You can then adjust for longer/shorter photo periods if needed to see what works best for your plants.

I also think Sue's advice about water changes is great. I did some frequent small water changes recently (for unrelated reasons) and my plants really shot up, even though I stopped fertilising for a couple of weeks.

If you have a relatively new substrate I wouldn't add any root tabs since there should be enough nutrients in the soil.

Sometimes it's difficult to determine the cause of what's wrong with plants. It could be too many nutrients and not enough light and CO2 or any combination thereof.

I'd see how the new water change scheme combined with the 8 hours of light work in the next 2 weeks or so. If these don't work, I'd try to lowering your fertiliser dose a bit.

The trick is to find the right balance between the amount of light, fertilising and CO2. Without CO2 injection (like in my tank too) your CO2 will be mainly coming from the air so that's your most limiting factor (liquid carbon helps, but can't replace CO2). The other two elements will need to be balanced to CO2.

You could start by next time a water change is due, use about 10% plain tap water added to your nitrate filter/RO mixture. That should be enough to give the plants some nitrate fertiliser without pushing the nitrate level up too high and stress the fish.
If you do this, measure the tank nitrate to make sure it is less than 10.

Hi,

30% (35lts) water change today (110ltr volume tank). Added 3 litres of unfiltered tap water (conditioner added). Started use of Seachem Flourish along with "liquid Co2". Will dose again tomorrow with Flourish and Co2. Out of the country from Monday back on Friday so will ask the wife to continue with the dosing of Co2 and Seachem.