Help - unrelenting algae

A

alarict

AC Members
Sep 22, 2008
6
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Bay Area, CA
:help: Problem: Algae.

I have blue-green algae, congregates on water surface particularly over CO2 diffuser, after one week it is thick. Film algae grows on tank walls and plant leaves clogging them badly. There is also an unattached, bottom floating brown algae that I remove from the tank floor when vacuuming the substrate. A little green spot algae appears a few days after a water change which I remove from the glass at water change, also hair algae removed weekly from glass (the tank is actualy acrylic). There is also brush algae on the rocks and the wood in the tank.

I have been playing with CO2 levels, ferts, nitrate levels, lighting times etc for over a year and end up with a different mix of algae from adjustment to adjustment. I can live with hair and spot algae but the other types clog up the plants and the tank as well as make the water change event take over 2 hours, disrupting the fish and making me focus on cleaning the tank rather than hovering the substrate.

The only way I have found to move pH below 7.0 is to leave the CO2 on all night. The tap water is slightly hard; tried adding a mineral remover in the bottom of the Ehiem but it made no noticable difference. KH measured 11 degrees once and pH at 6.4 which should have driven out most of the O2 in the water but the fish did not gulp at the surface and looked there normal fish-like selves.

Any help to end my mysery, remedy my igonrance and give my fish a better place to live will make all 32 of us happier carbon based life forms...

Tank Stats
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Size of Tank (Gallons / Lit res): 55 US Gal
Running since Aug-07

Water Params
-------------------
Temp: 78 - 82
pH: 6.9 - 7.2
Ammonia (ppm): 0
NitrIte (ppm): 0
NitrAte (ppm): 0
KH (degrees): 10
GH (degrees): 5
PO4: approx 0
Fe: don't test

Ferts you are using (what and how often):

Iron: Wed: 10mL Sunday: 12.5mL
Potassium: Wed: 5.0mL Sunday: 7.5mL
Nitrogen: 30drops every day
Trace Wed: 10mL Sunday: 15mL
Flourish* Wed: 2.5mL Sunday: 5.0mL
All Saechem nutrients... *Using the Flourish until it runs out.

CO2: Compressed Gas. 110 bubbles per minute (10lb, CO2 cylinder is 9 months old, 25lb/sq" pressure remaining).

Diffuser, in-tank with power-head and venturi.

Lighting (Wattage & type of bulbs): Two 48", 54 watt HO Florescent (this should equate to about 160watts). One bulb 6000k, second bulb 10,000k, Home made aluminium light fixture with contoured mylar reflector. 4 watt filament night light at one end.

Lighting and CO2 duration: 9 hours per day

Substrate: 75% gravel, 25% Flourite
-------------------
Fish In Tank:
25 Cardinal Tetras
3 Seraphae Tetras
1 Harlequin Rasbora
2 Clown Loach (both between 4-5 inches long excluding tail)
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Plants In Tank:
Lots of valisneria
1 Anubis (bubbles more than any other plant)
1 square foot of Java Fern (growing well)
Bacopa (struggling)
Cryptocoryne Beckettii - 2 large bunches several propogated bunches (struggling)
Amazon sword (just about surviving)
red stem plant that breaks the surace (growing well)
-------------------
Water changes:
Change 6 gallons, once per week. Tap water pH is 8+. Lower tap water to pH 6.8 before adding to tank using API pH down (has zero phosphates), Treat water with Novaqua plus (declorinator and sime coat only).
-------------------
Filtration:
Emhiem 2224 Professional
 
cyanobacteria tends to flourish and thrive in low/no nitrate conditions.

if your tank is so heavily planted that you cannot maintain a nitrate level above 0, i recommend dosing nitrate into the water column. keeping it at a steady level of 20 will really help the plants out, as well as give them the advantage over the cyanobacteria.

when you do this, also remove as much of the physical cyano you see, the less there is, the less there will be to grow.

Jm is right, adding ludwigia will really help with the nutrient advantage. Java moss (though slow growing) was a very effective algae deterrent in my tanks as well.

when you say you have a venturi on the powerhead, do you mean the co2 is diffusing thru the venturi, or do you have the venturi sucking atmosphere as well as the powerhead distributing the co2?

with a setup like that, you might look into a co2 reactor for better diffusion.

for the sake of the fish, start changing more water per week (ie.. 20-25 gallons or so), and stop using the pH down to lower the pH of the water. it's not doing anything useful, and as you can see the pH rises up to the level of the tank anyway.
 
JM, JRR, Thanks for the advice- I'm adding a small nitrate dose daily (so it does not spike) but will increase my daily dose to raise it, is the 20 you recommended ppm? The goal was for no more than 5ppm as I thought this was all the fish could take?

Will increase the amount of water at the change, this will let me vacuum the tank better also. I was changing 9g twice per week but a guy at the local aquatic shop said not to change so much water to let the tank stabilize.

The CO2 diffuser is like an upturned plastic can with the bottom end cut off with the CO2 bubbling in at the bottom. The power head pumps water into the top of the can and the venturi pulls CO2 back from the top of the can into the incoming water jet. It does not allow any atmosphere into the system.

Was aiming for a 6.8pH mainly because my fish prefer slightly acidic water and because the CO2 will absorb into the water better at lower pH's. Is it OK to let the pH go higher, it will probably sit at about 7.4 if I don't lower it in the incoming tap water? I can always leave the CO2 on after lights out to lower it?

ludwiga repens going in the tank tomorrow.
 
yeah, between 15-20ppm nitrate will be fine.. just make sure you keep a good eye on it as if it gets above 30 it is dangerous.

dont believe everything you hear at your local shops.. some have good knowledge, but always bounce that off another source before you heed. ;)

the pH will be fine at 7.4... MOST fish in the hobby are able to acclimate to a pH different than what they are native to.. if theyre tank raised, its likely theyve never even seen the conditions of their native waters anyway. :)

if stabilizing your nitrate doesnt help with the cyano, you can dose the tank with antibacterial fish meds to kill it (since it's a photosynthetic bacteria, not a true algae), but you have to be careful with that because it can kill the beneficial bacteria providing the cycle, as well.
 
JRR, Dr V, spot on.
Changed approx 20g, added 60ml of Nitrate to raise to 5ppm, will test again tomorrow and dose again until it gets to 15ppm. Lots of bubbles and none from the algae\bacteria (which I would have seen this many hours past a water change) - its looking good.:)

Your recommendation about the Fe sounds exactly the problem with the black brush algae. I was using the Flourish all in one nutrient then swapped to individual nutrients adding the Seachem recommended amount of Fe (25ml per week for my 55g). The black algae, which was dying off, started to grow back. I didn't have an Fe test kit (kit now on its way) and I guess this is one reason why you ask for this level as a diagnostic :). I didn't add any Fe at the water change.

One question, what level of Fe should I aim for?
 
Here is an update on this algae problem, just in case it helps others with similar symptoms...

Firstly, many thanks to JdoubleR, DrVader and jm1212 for their quick responses and expertise :thm:.

Based on the advice given, I made the following changes:

1) Raised Nitrate keeping to 10-15ppm by adding Seachem Nitrogen (all other dosing unchanged)
Effect. All plant growth accelerated noticeably, Java Fern and Vals especially, and Gigantica and moneywort appeared in the tank, which I thought had died off long ago. pH levels dropped and became more susceptible to C02 rate which was not the case with zero Nitrate. Algae that previously bubbled stopped showing any signs of O2 production.

2) Increased gallons per WC 2.5x. Did a major algae \ cyano removal.
Effect: Algae \ cyanobacteria did not re-grow at previous rates. Removed Black Hair algae and it did not grow back.

2) Added Ludwiga. This grows very rapidly and it complements all of the green in the tank, it has already needed pruning.

4) Tested Fe, it was close to zero at test but I decreased the Fe going into the tank anyway, no noticeable change in the plants. I read that Novaqua+ is not a good water dechlorinator for the planted tank as it neutralizes both heavy metals and metals needed by plants, particularly Fe (no idea if this includes chelated Fe or not). An email to Kordon did not help, so this is an unknown to research.

5) It has been over three weeks since I made the above changs and as above there was a period when algae was quickly regressing however a new form of green hair algae has started to grow on highly lit areas of the Vals. Additionally the Amazon sword that started growing quickly and healthily has started to show Ca deficiency (leaves are getting lighter in color and are crinkling at the edges, also the leaves are no longer straight with the central vein snaking slightly from the base to the tip). This is of course progress, the macro nutrient problems are under control, onto a micro nutrient deficiency :).

6) Another change in the works is to stagger micronutrient, trace and macronutrient dosing, apparently Fe will react with PO4 reducing their benefits and staggering them will reduce this.
 
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