Brown Algae

[smartin78]

I am having trouble with brown algae growing all over my glass and my plants (fake and real). I have read several things could cause this. Not enough light and over abundance of nutrients. I know I did not have enough light. I increase my light to 120w on a 75g tank. Is this enough. I know that is really not the recommended amount for plants. The only reason I put the plants in there was for the Silver Dollar to eat and evidentally he has become a carnivore or just doesn't like the plants. The plants I have are Hornwort and Anacharis canadensis. Will these plants continue to live with that wattage.

I was reading about nutrients and it mentioned silicates. What are they and how do I test for them?

I have Phos-x in my canister filter to remove the phosphates and nitrates. I was told the film that was forming on the top of the tank was probably from phosphates. The film is now gone.

My water parameters are as follows

75G
120w
Temp 78
PH 7.0
Ammonia 0
Nitrite 0
Nitrate 160 (Lack of knowledge caused my nitrates to be allowed to get this high. I am doing water changes every other day to help lower this. Will that help as well with the brown algae)

The brown algae seems to form fastest where the water is flowing. An example would be on the glass where the spout is shooting from my canister filter.


Thanks in advance for any help

[aquariumfishguy]

160ppm of nitrates can kill. Try to eliminate much of this – all the way until you get to 20-30 ppm. Then you are into the “safe” zone. Undoubtedly, this is why you are seeing so much brown alga. At least you are trying now that you’re learning.

120w in a 75 gallon tank would give you about 1.6 watts per gallon - if I did my mathmatics correctly. This isn't really enough light to grow many of the more moderate to high lighting required plants... but it shouldn't cause brown algae either.

[smartin78]

Would you recommend I do a large water change now instead of many smaller ones. I have done about 5 water changes and am still over 160 PPM. I am changing about 20% each time. I was afraid a large change may be to much for them. I do have a pair of Kribensis that just laid eggs 2 days ago. I was out of town for this. I wish I could have been there. Anyway I do not want to stress them out with a big water change. Also my tap is high in chloaramin. I put stuff in the water that removes chloarmine but even so my chemicals go out of wack for two days. Day one Ammonia registers high. Day 2 nitrites register high. Then as the bacteria catches up by day three all is ok. The LFS said this is normal in my area.

Would I be able to support low light plants with that WPG? Mayba java moss or something like that?

[aquariumfishguy]

I would do a minimum of a 50% water change… the reason being that you do have fish in this aquarium who will really need better water. You can’t bring things down too quickly, but if you can bring nitrates down 30-40ppm at a time, this would work. Changing large volumes of water should not stress healthy fish.

At the level of wattage you have right now, you could keep low light plants. They might not thrive, however. It just depends on the plant in question.

[Damon]

1.6 wpg should be more than adequate to grow anacharis and maybe hornwort. I would suggest anubias bar, crypts, or java fern. Brown algae is cause by any of 3 major factors.
1. Low water movement
2. newly established (or cycling) tank
3. Water high in silicates (very common)

If your tank is still relatively new, just scrape it off and do your water changes. If it has been around for awhile, Increasing the light or water movement should also do the trick.

[smartin78]

The tank has been up and running for 8 years. My totall gph water movement is 740. Is that enough for a 75g? Like I mentioned earlier. I uped my Light form 40w to 120w today. Should that be enough. Also could you explain how I would know if it is Silicates and what I can do about them. I am going to do a 50% - 75% waterchange right now .

Thanks Again

[soccermouth]

My experience with hornwort/anacharis is that you can grow it in just about any lighting. Those should work quite well.

[Damon]

Your flow seems fine. Are you overfeeding? Lighting shouldn't be the cause. Lower your nitrates like stated above.

[aquariumfishguy]

Yes, your filtration turnover rate is about 9.8 - that is pretty good. Also, with brown algae, it is almost always a form of silicate. But this is still in fact algae.