Bga....one Last Time...

[Rorie]

Ok, my BGA has returned. Here is all the data you need about my tank. I have heard many conflicting stories about having too much/too little Nitrate...low or high GH or KH... etc etc. What can i do?!

360L tank - 52"x18"x24"
for 54W lights six inch above the tank - 24" above substrate. (added 2 weeks ago to add extra light for my carpeting plants....seems to have done the trick) on for six hours a day
two external filters, 1200 l/h each
two powerheads, 900l/h each creating movement in all parts of the tank (can see all the plants/moss waving)
a pressurised CO2 kit which is distributed through a diffuser and spray bar. Even distribution throughout tank - lime green indicated. On one hour before and off one hour after lights
Dosing "tropical Plant Nutrition", "Tropical Plant Nutrition +" and "Easy Life Kalium". Both tropical doses are split over the week, Kalium added once after water change.
Water changes are 50% once a week - tap water added directly and the whole tank is dechlorinated
Tank is heavily planted

Tank Stats:
PH 6.0
Ammonia 0
Nitrite 0
Nitrate 40PPM
GH 4
KH 1

Stock:
20 corys
4 otocynclis
Zebra Nerite Snails
4 bolivian rams
50 cardinal tetras
4 large discus (6-7 inch)
3 small discus (4 inch)

My discus and rams spawn regularly. All fish have been healthy since day 1

 

[StandbySetting]

Where is the algae occurring? I'd only run 2 of the 4 tubes, slower carpet growth is much better than algae, also I make your circulation to be 4200LPH on paper, in reality it is probably about 2500-3000LPH, you might want to replace the current powerheads with more powerful ones (Are you using Koralia nano's?, I'd upgrade the larger models), I tend to aim for about 10-15x actual turnover. What is CO2 distribution like? Have you moved your DC about to check for any 'dead spots'?

You might want to switch to EI instead of TPN+, TPN+ is mainly composed of Ammonium Nitrate, as you know Ammonia/Ammonium can cause algae, which is one of the reasons why I used Potassium Nitrate instead.

 

[Rorie]

I used to have larger Koralias, but this was a bit nuts, so it was previously advised to replace them with smaller ones. I think this is still an awful lot of flow?!

I never thought it was BGA which was caused by too much light? I have normal algae caused by the excess of light, but can deal with that. But the BGA has come back in the last two days

CO2 is distributed well. Got 3 DC and move them about the tank. It is VERY evenly spread!

The power heads ensure flow is even throughout the whole tank.

The bga is on my carpet, and the java moss on my wood.

I previously used EI, but wanted to see if dosing premixed, over priced stuff would get rid of my problem - which would explain that it was me dosing wrong or something....but clearly that is not the case.

What about Nitrate? Too much, not enough? How can i have algae when my CO2 is as high as i can put it?!

 

[StandbySetting]

All algae is caused by light, algae is a more adaptable organism than plants so light will further accelerate its growth as it can utilise nutrients faster than plants can.

Try moving one of your powerheads so it is blowing CO2 and nutrients to the bottom of the tank and this may fix the problem, many high tech set ups with CO2 can experience algae problems, it is normally a flow/ammonia issue that causes it.

Have you tried a black out to kill as much as possible before implementing the new techniques?

Your nitrate is fine.

 

[Rorie]

yeh did the whole black out thing, and it went away for a few weeks. thats when i added my new powerhead. so thought it was solved.... grr...

my carpet plants didnt grow at all in 5 months! hence the extra lights, and for the first time i have seen green shoots! so i need the light....

 

[StandbySetting]

The fact that they're not growing could have been due to limited nutrients at the substrate level, adding light will accelerate growth, as the plants will grow rapidly using stored energy in order to find nutrition. You really don't need a lot of light to grow HC, Glosso etc, they just appreciate CO2 and nutrients more than most other plants do.