Cause of brown algae?

[Puddle]

Following a thread I placed previously about BGA, I conducted a blackout and dosed ferts and the BGA disappeared. I have since got a very small area of BGA but it is not getting worse or bigger so I am going to rely on the good old snails to help me with that . BUT I have now got a light covering of brown algae on some plants, pepples and rocks. Could anyone tell me what may be causing this? After I last tested, results were:

NO2 0
Ammonia 0
NO3 5mg/L (Can't seem to get it any higher at the moment even with dosing with TMG/Plant Nutrition +)
PO4 1mg/L
pH 7.6

Any help gratefully received!

 

[JDogg]

ok to make a proper diagnosis i am going to need some more information...

how much light are you running?
CO2?

it the "brown algae" a powder that is easily wiped off, or is it more like fuzz that is hard to get off?

how long has the tank been set up?

my guess with out the above info is you have diatoms, which are not really algae but tinny one-celled silica eating critters. if your tank is newly set up then this is a perfectly natural stage in its maturation, the diatoms will go away on their own, once they use up the free silica.

p.s. if low NO3 is causing you a problem (since you have been fighting BGA i would say it has) you might want to pick up something like Flourish Nitrogen, i am not familar with the product you are currently using, but i am sure it does not contain much, if ANY, NO3.

 

[Puddle]

Thanks for the fast response! I have 1.5w/g lighting so not high. The fert has nitrogen in it at 1.34% and PO4 at 0.1%, I got it after suggestions to increase the NO3 to help the BGA, as I have more plant than fish load. The difference in the plants has been amazing as well, though some leaves are turning brown at the tips/edges (any ideas why?).

To be honest I haven't had a scrape at the brown stuff yet so not sure if it is hard or easy to remove, but its not really fuzzy. The tanks been up and running about 4 months now, is that about the right time to see the 'diatoms'?
Thanks again

 

[JDogg]

Thanks for the fast response! I have 1.5w/g lighting so not high. The fert has nitrogen in it at 1.34% and PO4 at 0.1%, I got it after suggestions to increase the NO3 to help the BGA, as I have more plant than fish load. The difference in the plants has been amazing as well, though some leaves are turning brown at the tips/edges (any ideas why?).

how much K and Fe are in your fert?

To be honest I haven't had a scrape at the brown stuff yet so not sure if it is hard or easy to remove, but its not really fuzzy. The tanks been up and running about 4 months now, is that about the right time to see the 'diatoms'?

could be, different tanks go through the stages at differnt speeds

 

[Puddle]

Total fert constituents:

N 1.34%
P 0.10%
K 1.03%
Mg 0.39%
S 0.91%
B 0.004%,
Cu 0.006%
Fe 0.07%
Mn 0.04%
Mo 0.002%
Zn 0.002%

Recommendation is to add 5ml per 50L, I have a 180L tank but initially started with putting in 10ml/wk, which I recently upped and changed to 5ml 3 times a week as some leaves still looked a bit brownish.

 

[Jchillin]

Sounds like a bit of diatoms. Do you have any water movement where the algae is accumulating?

 

[Puddle]

Yes its pretty good, if I got the PO4 a bit lower would that help or do you think it will go away on its own as silicates decrease?

 

[Purrbox]

Sounds like you need to up your dosing. The recommended level is probably more conservative than what your tank needs.

I'd recommend switching over to individual ferts for the Macro Nutrients. That would give you more control over how much you're dosing of each. Since you're in the UK I'm not sure what exactly is available in your area.

 

[Puddle]

That was the reason why I got a good general fert with NO3 and PO4 included. What level should PO4 be at again? I wondered if the increase in PO4 may be causing the diatoms? I know I could have more NO3.

 

[JDogg]

That was the reason why I got a good general fert with NO3 and PO4 included. What level should PO4 be at again? I wondered if the increase in PO4 may be causing the diatoms? I know I could have more NO3.

in general you should be dosing around 20-30 ppm NO3, 20-30 ppm K, 2-3 ppm PO4 and 0.2-0.5 ppm Fe as a weekly total, pair that up with a 50% pwc

 

[Puddle]

I read that Diatoms occur in tanks with high nitrates and phosphates with a pH over 7, is there any truth in this?

 

[Purrbox]

Jdogg already mentioned why Diatoms occur. Silicates pure and simple. Once the silicates have been consumed, the diatoms will go away on their own. If diatoms are a persistant problem that don't go away after a couple of months then you need to look at what might be introducing silicates into your tank.

Now if you're dealing with something other than Diatoms then it needs to be identified so that we can help you determine the cause.

 

[Jchillin]

No, it's usually due to low light levels and an abundance of silicates. Since you have 1.5 wpg, it may be due to not having the lights on long enough.

 

[Puddle]

Thanks again for your help guys!

I recalibrated my PO4 test kit, and turns out it was a bit off so my PO4 was more likely to be 2.5mg/L (not 1mg/L as I wrote before) :? . NO3 levels are 5-10mg/L but haven't calibrated that one (nothing available at present to make solutions with!).

I know I have high PO4 in my tap water (5mg/L or more) so I'm guessing silicates may be coming from there as well . I have replaced the phosphate media to reduce the silicates. I know its weird to add PO4 by tap water, to remove it with media to add it with ferts to required levels but its the best I can do until I get some water with less PO4 or RO, remove the PO4 media and dose ferts as required!

Lighting is on for 10hrs/day, I have no other algae issues, the BGA isn't doing anything so it'll probably decline as I fert the plants better! Talking of which the plants are looking a bit sad, once I started dosing they all grew like weeds and looked v healthy, now some leaves are brown at the tips/edges, including old or new leaves, could this be due to fert deficiency now that they are growing better?

Thanks again, any thoughts appreciated!

 

[Purrbox]

How long has it been since you replaced the bulbs in your light fixure? Might be that the bulbs are just getting old and the light spectrum has shifted enough that the plants are no longer getting enough light.

 

[Puddle]

I started using the lights in January, was a brand new tank, so they have been in use for only 4 momths?

 

[Hoovercat]

I don't feel light is the problem. Either too much or too little. Planted tanks are simply prone to this problem. I have killed diatoms by blacking out the tank though. Not a complete blackout just turned the lights off for a couple days. No science just an anecdote but it might help you get things under control.

Ottocinclus catfish will eat this algae as well. I would get 1 per 10 gallons of tank size so 5 should work in 180 liters.

You can source your needs for DIY ferts at hardware and garden supply stores or any hydroponics supply. You'll need KNO3 (potassium nitrate) which is commonly sold as stump remover, K2SO4 (potassium sulfate) which is sold as sulfate of potash, and KH2PO4 which is sold a home use enema preparation at the apothecary's. In the US it's sold as Fleet enema.

The KNO3 can be used to make a test solution for nitrate as well. This page will explain how to use these products to fertilize your tank http://www.rexgrigg.com/dosing.htm

Does anyone have the link for Chuck's aquacalc? I can't find it on his site anymore.

 

[Purrbox]

Does anyone have the link for Chuck's aquacalc? I can't find it on his site anymore.

Online
Windows Version

 

[Hoovercat]

Thanks Joy.

Okay, Puddles to make a NO3 test solution first take 1 3/8tsp or 7.73 grams of KNO3 and dissolve it in 250ml of water. Next, add 1ml of this solution to 1 liter of water. Measure a sample of the liter container and your result is 20mg/l of NO3. Even if it doesn't match your chart, adjust the chart because the solution is 20mg/l.

Be sure to install chuck's calc (Purrbox's Windows version link). It will help you calculate dosing for your tank so you can keep nutrient levels adequate. Keeping NO3 in particular available at all times will keep BGA from coming back.

Most everyone on our forum uses dry ferts so we can help best if you do the same. Very few of us have had enough success with a "comprehensive" fertiliser to give good advice on how to get your tank running well using such a product.

 

[kickeralpine]

not that this is a fix for you but to clean it up ottos work wonders with brown alge had it bad after my tank cycled and 5 ottos cleaned it up quick and never came back