Victory against green fuzz with H2O2

[Aeon]

My mistake in assembling the CO2 reactor wrongly.
Main Eheim 2028 filter flow stopped/reduced to a trickle. Suspect motor problem.
Didn't have time as I was rushing for meeting, left it like that for a few hours.
Attached a hang-on filter with new media to increase filtration slightly. Running for at least a day.
Attached 2nd filter Atman CF-1000 with old media which must have been starved of O2.
Finally after 3 days and fiddling with the Eheim 2028 and lots of water on the floor, I managed to figure what's wrong and got the flow back.
2 filters running simultaneously with most of the medium in Eheim 2028. Atman has some bio rings and 2 bags of Carbon.

Green Fuzz Horror
There has been a little bit of green fuzz algae on the glass before that. After what happened, green fuzz started to spring up on rocks, Eleocharis acicularis, Eleocharis vivipara (newly bought, converting from emmersed). Soon enough almost everything was noticeably covered within 5 steps away.
Must have been the death of beneficial bacteria and causing spikes in NH4. Testkit ran out so couldn't test so I just assumed.
Many of my shrimps also died and i'm left with just 1.

H2O2 Option
Not convinced to use algaecide, i did a lot of reading up. After a considerable amount of research and reading through other people's experience, I decide to go the H2O2 way.
With only 1 shrimp in the tank, I chose to proceed with dosing without transferring him to another tank.
Source of H2O2 was Hydrogen Peroxide 3% BP solution I got from Guardian. $3.50 or so for a jar.
I poured some H2O2 into a beaker. Then use a small and narrow 1ml syringe (pic) to slowly administer H2O2 directly onto rocks, acicularis and vivipara. 1 full syringe is about 1m so in total I used about 6-8ml, didn't count.
Within minutes, the green fuzz started bubbling profusely. (video) Dead clumps of green fuzz floated up.
The next day, nothing died except for the green fuzz which came into direct contact with H2O2. About half the green fuzz were killed. The shrimp didn't die.
I added about 30 Yamato shrimps in the morning. I continue with a similar dosage of H2O2 in the afternoon.
The next day, green fuzz was almost finished off. As I didn't acclimatise the shrimps properly, some jumped out of the tank. I don't think it is due to the H2O2.
The 3rd day, I decided to switch to Excel instead of H2O2. About 6 caps of excel applied with a syringe direct onto litle green fuzz which survived the H2O2. Green fuzz didn't bubble nor the kill was swift. Continued the morning excel treatment for about 3 days and 95% of green fuzz was gone. Even the persistent ones on acicularis.

Now my water tank is 95% algae free except for some green dust and a bit of green fuzz on the glass which came when I switched off the fan for ich treatment for my green neons.

Conclusion from this experience
H2O2 kills green fuzz algae and probably most other algaes with minimal hazard to other critters compared to algaecide.
H2O2 has no adverse effect on Glossostigma elatinoides, Riccia fluitans, Eleocharis acicularis and even my recently trimmed Eleocharis vivipara which was still converting from emmersed form did not melt.
Excel helps after an initial H2O2 treatment as a milder but effective approach.
Yamato shrimps eat dead algae at night.
An increase in temperature from 26degC to 30degC caused green dust and green fuzz to form on glass. Lowering the temperature stopped its growth.
Having an Atman CF-1000 (1350l/hr) + an Eheim 2028 (1050l/hr) did not cause a tornado in my tank, the flow was rather good or better than having just 1 filter.
The increased water flow helped in curbing the algae.

[yeoyl87]

H2O2 friendly on moss? Hmmm... lower temp = low algae? Any bro can confirm this?

[Aeon]

Moss not sure. But you can do some reading.
As for lower temp, I feel that higher temp speeds up things, like chemical reactions. So higher temp = things happens faster, algae grow faster.

[Biotopeshop]

Moss not sure. But you can do some reading.
As for lower temp, I feel that higher temp speeds up things, like chemical reactions. So higher temp = things happens faster, algae grow faster.

Hi Aeon,

We had a similar experience with low temperatures too. Every time when the water gets cold, the plants flourish and the algae disappear.

regards

Thio

[Aquaculture]

Good observation. As coldness set in, growth rates slows down. Therefore giving us a window opportunity to rectify stuff.

[Shadow]

Hi Aeon, did you turn off your filter during the whole process? Will H2O2 kill the beneficial bacterial colonies in the filter media?

[Aeon]

Didn't turn off completely, but the flow really became a trickle as the reactor assembled wrong and blocked the flow. But while I was spending half the day fixing stuff, the filters are turned off as I need to take them apart.

I didn't observe any significant signs of ammonia increase after applying H2O2. I believe H2O2 will harm bacteria also but because I was doing spot treatment, the H2O2 mostly stayed on the spot and didn't get carried around. Yes I off the filter also. This way the H2O2 has time to kill the algae and by the time it enters the filter, it had become H2O and O.

[K11]

Hi Aeon, where you get those small syringe? I might try this H2O2 method to kill off algae in my tank, think its should be hair algae.

[Aeon]

Hi Aeon, where you get those small syringe? I might try this H2O2 method to kill off algae in my tank, think its should be hair algae.

You should be able to get those syringes from where you get H2O2, e.g. Guardian. Unity. Try it!

[K11]

Hey, tried this H2O2 method on the hair algae and they slowly turn white after one to two days, and the livestocks are not affected.

The last last time I used excel, (it kills off the hair algae and BBA pretty well) my livestocks went out of breath and had casualties.