rms said:
Yes I have pressurised co2 with drop checker, which practically glows bright green (unlike my plants
), so I suppose my co2 levels are good.
Unfortunately, this may not be the case. Drop checkers are just a rough guide, and can very often be wrong. Plus, they only show you CO2 in one point of the tank - and obviously not at the exact point it matters most and will be at its lowest - around the plants.
I'm using salts and trace elements from The Nutrient Company. I'm dosing daily, 5 days per week, as per instructions. 2 days off followed by a 50% water change on the first day of starting the 5 day dosing.
You mentioned your nitrates are only at 10ppm - this indicates to me that your not dosing that much KNO3. I'm not familiar with TNC's dry salt instructions, but they are likely on the conservative side. This article should clear some things up
:
http/www.ukaps.org/index.php?page=dosing-with-dry-salts .
My filtration is more than adequate, I have a Fluval U3 and a crappy Chinese big enough for my tank as well. I use that one for co2 diffusion as well as for use in quarantine/hospital tank when needed. My drop checker is placed in the hardest to reach part of the tank for water flow, so I know filtration and circulation are not an issue.
Ah, but filtration is not the issue. Its the distribution of oxygen, CO2 and all other nutrient to the plants. From your pictures, I can tell that you don't have nearly enough flow from the debris in the brown diatoms growing on the plants leaves. You don't mention the volume of your tank, but the Fluval U3 provides a
laminar flow of well under 600lph if it contains media, or a very low flow from a spraybar. The same for the Chinese filter - the pumps lph rating is very optimistic in the first place, and doesn't account for the media in it, and only provides a laminar flow, or a greatly reduced flow from a spraybar.
Most high tech planted tanks nowadays feature modern circulation pumps, like Hydor Koralia or Fluval Sea pumps. These provide a massive flow rate, but spread over a much wider area so its not a problem for fish and it distributes CO2 more evenly.
As I've just mentioned in another thread, low flow is one of the most common reasons people have poor plant growth or algae issues.
Oh.... The lighting should be fine. I have two Phillips TL-D 18W. Please tell me they are fine...
2 X 18W of any type if absolutely perfect for the plants
. Though I have no idea about the appearance of those tubes to the human eye, is there no more details on the tube? TL-D is a whole product range of Phillips T8 tubes - from fly-attractors to meat-display tubes, so need to know more details really. Could you maybe take a picture of any writing on the bulb, or type it?
But what you need is certainly more flow (I'd highly recommend a circulation pump for Christmas
), and possibly upping the dosage of ferts if that EI article helps at all
. Also, increasing CO2 slightly may help a little too, but do this very slowly and watch the reaction of the fish very carefully. It may not be worth doing this until you improve flow, however.