The Planted Tank Forum banner

The "One-Two Punch" Whole Tank Algae Treatment

411K views 546 replies 219 participants last post by  Dallascowboys16 
#1 · (Edited by Moderator)
NOTE: Others have reported deaths of shrimp, snails, and fish - particularly known sensitive ones. Please read the entire thread for details before experimenting. For anyone who wishes to try this, I am changing my initial recommendation for H2O2 to 2 tbsp. per 10G, down from 4 tbsp. This treatment seems especially hit-and-miss with shrimp, so for them, I do not recommend this treatment AT ALL - unless you consider them expendable.


PREFACE:


This is a technique I've developed. While I've provided this info in several threads now as personalized help, I feel it deserves a full write-up in its own thread.

In brief: It uses a properly executed H2O2 whole tank treatment, followed by a whole tank Excel treatment, to provide a much greater algicidal effect than either alone; without noticeably increased risk to fauna or plants.

This has been performed by me many times, and by others only a few. While in all cases no adverse effects were observed, I cannot guarantee it to be 100% safe. Only through many more tests in a wide variety of tanks can that be established. Keep that in mind should you decide to try it, and if you do, please share your results in this thread.

Even if you don't try this, you may still find some of it informative.


FIRST PUNCH: H2O2

Whole tank H2O2 treatments don't get much attention. The results are typically very poor, at least until you get into such doses that fauna are at risk; and after a few failed attempts, most folks understandably write this option off.

But the truth is, most people perform this treatment completely wrong.

The WRONG Way:

Typically, the first thing done is to turn off the filters and lights. Already, one mistake has potentially been made, and a path paved to another.

Turning off the filters does prevent H2O2 from flowing through the biomedia. That's good, because we don't want the H2O2 to kill too much nitrifying bacteria, nor want the H2O2 depleted at this point in reaction with these bacteria. But often, this leaves little or no flow in the tank.

The effect of any chemical is determined by: Concentration * Flow * Time.

A H2O2 spot treatment works with no flow, solely because of the incredibly high concentration at the location where it's applied. But in a whole tank treatment, it's far more dilute. So instead, high flow is required to carry it around the tank, to contact the algae and have some positive effect.

Without that, there is only one place where high flow is occurring. Fish gills. And that is the one thing we don't want the H2O2 reacting with!

Moving on now. The H2O2 is added. Some amount of time is allowed to elapse, a half hour or so. Then the treatment is "terminated", by turning filters and lights back on. This is the next mistake.

Virtually all of the H2O2 still exists in the tank, because without flow, very little of it has reacted with anything. While light does break down H2O2, this is measured in days - even in direct sunlight. Not minutes. So the light has no effect, in the time scales we're working with.

The biofilter at least is now reducing the H2O2. And with flow restored, the H2O2 is at last starting to have some effect on the algae. But the fish are already getting close to suffering noticeable stress. The full concentration of H2O2 has been flowing through their gills for a half hour, completely without reason since this time did nothing to kill the algae. And they will continue to be exposed to gradually lessening concentrations, further increasing the stress, as the filter slowly removes it. It may take another half hour before H2O2 is sufficiently reduced.

The RIGHT Way:

As I said before, Concentration * Flow * Time.

So if you want an effective treatment, provide massive flow during the entire treatment period. Since flow is constant through fish gills, to protect them you shorten the time, by wasting none of it with periods where the algae isn't affected, and correctly terminating the treatment. If this is done, the increase in safety is actually enough that concentration can be increased.

First, prepare the tank. You want as much flow as possible. If you have extra powerheads, add them. If your sole source of flow is your filters, you'll have to temporarily remove the filter media to a bucket of tank water, and leave the filters on. Otherwise, this is optional but still beneficial. I have a cheap Koralia clone that with 1,320GPH flow, turned out to be too much for any of my tanks; but I keep it around because it's ideal for this treatment.

If you have Marimo balls, temporarily remove them to a bucket of tank water as well. Cladophora is very hardy, and normally not affected by whole tank H2O2 treatments. But this treatment can burn them badly, especially on sides exposed to direct flow. If they're also infested with undesirable algae, they can be treated simply by keeping them in the bucket in a dark place for a week. They can tolerate extremely long blackouts without harm, unlike other algae.

Keep the lights on. Light has no effect on the H2O2, only your ability to see what's going on.

Now add 3% H2O2, at a dosage of 4 tbsp. per 10G of actual tank water volume (excluding substrate, plants, etc.). Yes, that's double what's typically used; as explained previously we can use a higher concentration.

Allow to circulate for 15 minutes. During this time, redirect flow a few times if possible, to make sure all areas get covered. If you have particular trouble spots, try to ensure they get direct flow during part of the treatment.

Now terminate the treatment. Do a 50% water change, or more if you know it's well tolerated. Return the tank to its normal configuration, including replacing filter media if it was removed.

Less hardy algae may be effectively killed by this alone, especially if flow was good. But all algae will be weakened, and now it's time for:


SECOND PUNCH: EXCEL

Any remaining algae not killed by the H2O2 is now extremely susceptible to Excel.

If you weren't already using Excel, or were using it at the recommended dose, add Seachem's recommended initial dose of 5ml per 10G. No further large doses are necessary in this case. Algae builds up some tolerance to Excel, similar to sensitive plants like Vals. In this case, the H2O2 treatment followed by a single, sudden Excel spike is enough to quickly finish algae off.

If you were already using Excel overdoses, continue using the previous dose.

Enjoy your algae-free tank. If there are any underlying problems that caused the algae outbreak in the first place, correct them so your tank stays algae-free. In some cases, a thorough algae removal like this is enough to improve plant health to the point where algae will not return.


CLOSING NOTES:

I've used this treatment many times over the course of the last year.

It was originally developed to deal with what I call my SOS, "Staghorn On Steroids", as featured in my signature. SOS doesn't behave quite according to the rules. Like most algae it likes high light, but will thrive in medium light if flow is high. It laughs at high CO2, H2O2 spot treatments, and Excel spot/tank treatments. But it falls hard to the "One-Two Punch", and I relied on this treatment heavily when trying to figure out how to keep it from growing. Which took a while, during which time I probably would have given up in frustration if I hadn't found a way to periodically eliminate it, without ripping out half my plants after each failed tank parameter adjustment.

I've tried it on other algae too, mostly out of curiosity rather than necessity. Works great. Burning my Marimo balls was a nasty surprise, but certainly showed how effective it is, as they've never been affected by any other algicidal treatment. Should I ever have an invasive clado problem, I expect this might be able to eliminate it.

I've never seen any adverse effect on the more sensitive inhabitants of my tank; including otos, cories, bamboo shrimp, ramshorn and pond snails. No idea if it's safe for other shrimp, as I keep no other varieties. I'd like to see someone try it on a tank with a few expendable cherries. Java moss was unaffected. I have some anacharis, which is particularly sensitive to Excel, but which I've gradually acclimated to a normal dose; it too is unharmed by this treatment. Hopefully others can soon add their experiences.

Off-topic but related. Recently I see the use of AlgaeFix being more freely discussed, now that certain people have finally softened their views on it, and mentioning it no longer results in guaranteed chastisement. Yes, it works, I've used it, and it's certainly easier than my method. But it isn't safe for invertebrates. Several times I've also had fish severely stressed or killed by AlgaeFix, and although in the majority of cases this doesn't happen, I consider it a gamble. I have an idea why this occurs different from other hypothesis I've seen, and how it might be avoided, but that's a topic for another thread I'll soon post. At this time I consider my treatment possibly safer than AlgaeFix when a powerful full tank treatment is required, and certainly usable in more circumstances.

Hope this proves useful to you!
 
See less See more
#5 ·
I wish I'd seen this before tearing down my old tank as I never could get the black bush out of my fissidens. I've been trying a blackout but the moss seems to be losing the fight, so perhaps I'll set up a couple powerheads in my quarantine bucket and give this a try as I'd really like to salvage what's left of the moss.
 
#8 ·
I nuked my tank tonight, several hours on and things look like they are still 'fizzing.' Is this normal?
It's normal. When H2O2 reacts with organic material, it produces oxygen - lots of it. The H2O2 is essentially gone at this point, but it takes a while for all the excess dissolved oxygen generated earlier to slowly bubble out of solution.

The 50% water change, if performed with tap water, is also loaded with dissolved gasses. Chances are, you've heard of or witnessed "false pearling" after a water change.

In this case, because both the old and new water are saturated with gasses, it can be quite a show.
 
#9 ·
This is a great write-up! Thank you!

I've been having some algae issues and I know it's related to the inconsistent nature of my DIY CO2. I'm almost done building a pressurized system and should be up and running before the end of the month. It's good to know that I have a way of nuking all of it and starting over when I switch over. It'll be a lot easier to monitor what's going on.
 
#12 ·
Which algae is this good for ? Is there any that you would consider this a waste of effort on ?
It appears to be good for anything except hard spot algae. With those, any chemical treatment only kills the outer layer; which, since it takes a few days for the killed portion to flake away, effectively shields the remainder from exposure. So an effective treatment only shrinks a spot.

I've completely removed heavy spot algae from both an anubia leaf and a resin ornament, mostly just to see if it could be done. It took somewhere in the range of seven H2O2 spot treatments, over three weeks, for complete removal. Definitely a waste of effort!
 
#14 ·
Playing devils advocate, What would be a good preventive measure besides water changes and lower light periods paired with sufficient bps of co2? I for one would not discount the hammer approach but often find prevention and preventive measures more fruitful in the long run and less dramatic/intensive for all involved parties.
 
#17 ·
caution / concern on my part from past trials.
1 US tablespoon = 14.7867648 ml
Recommended here is 4tbs/10g or 6ml/g

Treating external fish problems I've used and posted dosing H2O2 @ 10ml/g for a fish bath.
Contact with organics & time are indeed what break it down not light just as you posted.

1 US teaspoon = 4.92892159 ml
2 teaspoons of H2O2 per gallon is perfect for the scaled fish treatment I needed. Problem though with scaleless fish like loaches along with L144 and LFABN (Ancistrus) not tolerating it well at all (will jump right out of the tank).

just FYI because 6ml/g isn't that much lower than what I know caused problems for some of my fish.
 
#19 ·
caution / concern on my part from past trials.
1 US tablespoon = 14.7867648 ml
Recommended here is 4tbs/10g or 6ml/g
This is a valid concern. Some thoughts on it:

With vigorous flow, the H2O2 concentration does not remain at the initial dose for the entire treatment time. It will be reduced not just in reaction with algae, but also quite rapidly at first in easier reactions with omnipresent bacterial films and organic wastes. So this cannot be compared exactly to a medicinal dip, or any H2O2 treatment where little or no flow is present.

Because of this, in a tank with good flow, the dosage has an exponential rather than a linear effect. Too small a dose, and it will be so rapidly consumed that it has little effect on algae. Too large a dose, and after easily reacted materials are depleted, the concentration stays high enough for the remaining time that fauna may be adversely affected. Tricky, eh? :)

I've tried many different dosages and treatment times, and I believe my recommendations to be the "sweet spot".

Increase to 6 tbsp./10G for 30 minutes caused lethargy and hanging around the surface in some fish, though there were no deaths and all symptoms disappeared within a day.

Except for the above increased dose, I've had no problems with my golden and weather loach, which I didn't think to mention in my original post because I don't consider them particularly H2O2 sensitive. The crazy things insist on playing in H2O2 spot treatments, seemingly without harm!

Still, if anyone prefers or feels more comfortable with a lower dose, by all means use it. The effectiveness will be somewhat reduced in my experience, but still adequate for anything but tough algae. The efficacy of this treatment is not due only to higher H2O2 dosage, but to good flow and combination with Excel.
 
#18 ·
Thanks for the method, I tried it yesterday, and it looks like the BBA is fryed. A few tricks I tried.

You can use a cup to manually create extra flow during the 15 minute H2O2 treatment.

If you take some of your old water out (just clean water off the surface) and set it aside before treating the tank you can 1) increase the effectiveness of your tanks pumps + filters. 2)dilute the H2O2 concentration faster after the treatment, with less of a shock in parameters from a big water change. For example, take 5 gallons out of your 10g, now treat the remaining 5 gallons with 2 tbs H2O2, then after the treatment, take out 2.5 more gallons (discard), leaving one 1tbs worth of H2O2 in the tank. Add the old tank water back, and 2.5 gallons of new water. Gives you the H2O2 dilution post treatment of a 75% water change, while only doing 25%.
 
#23 ·
Higher is better. Beyond that, it's hard to suggest any meaningful lower and upper limits. I can at least provide the tank setups used for treatments.

The majority were done in a 46G bowfront, with between 1,320GPH (Koralia clone) and 1,620GPH (Koralia + Penguin 1140 powerhead).

Some others were done in a 10G, dual Aquaclear 20 HOBs with media removed, rated for 200GPH combined.

As for fish safety, if they're stuck to the powerhead intake and can't get free, it may be too much flow. ;) Seriously though, they can tolerate very high flows for 15 minutes. Much higher than they could tolerate continuously, as fatigue eventually sets in from fighting the current.
 
#25 ·
Datapoint:

I used this protocol yesterday and some of the BBA is turning reddish. Not all though, so perhaps this will require a couple of treatments. I will space them out by at least a week or two.

I did not turn off the filter and I did not take out the media. As predicted, the biofilter took a hit and I had some ammonia this morning. Nothing that a 50% water change didn't fix though. Next time I will unplug the filter and rely only on the powerhead for flow.

Fauna are fine although they did show a bit of distress around the 13 minute mark. My livestock consists of:
Cardinal tetra
rummynose
ottocinclus
bushynose pleco
Congo tetra
apistogramma cacuatoides
kuhli loach
cherry shrimp
assassin snail
 
#27 ·
An interesting idea. Though I'm not sure how much of an effect it will actually have on the treatment.

Flow doesn't penetrate very well into substrate, even if loose. For this reason, if you have algae growing on the substrate, I don't recommend turning it over prior to an algicidal treatment.

If you have lots of mulm on the surface of the substrate, then removing it would result in less H2O2 depletion.

Of course, if this is the case then a gravel vac is just good tank husbandry, regardless of treatment. Same goes if you have excessive buildup of mulm in deep substrate where there are no plant roots. No chemical treatment replaces proper tank maintenance.

On a tangent, sometimes I get buildup of mulm in the substrate visible from the front glass, in areas where gravel vacs aren't practical because there's plants and roots in the way. If it gets too ugly I measure out 2 tbsp. per 10G of H2O2, and inject it deep into the substrate along the front with a syringe, in approximately equal applications every inch or two. The mulm, broken down and more readily absorbed, disappears within a few days. You'd think this might burn the roots, but oddly I've seen no negative effects. Except for Marimo balls. Move them at least 6" away from the area, the prolonged exposure and high concentration will burn their bottoms.
 
#30 ·
Sorry to hear about the cherry. Hopefully there will be no more deaths. Though I'd consider even one death to be an indication they may need to be treated as a special case, with reduced dosage.

The vals aren't a big surprise, as they're notably sensitive to Excel. Were your vals already pre-acclimated to Excel, or is this their first recent exposure? Which Excel dosage did you use?

Looking forward to further updates.
 
#31 ·
No worries about the shrimp, there are plenty more. As for the Val's, I have dosed Excel before. I followed the protocol as described with the following caveat:
I have a 75 gallon tank with a bunch of wood so I 'guessed' I had 60 gallons of water. I have never actually measured it.

All in all, this looks to be an effective treatment as long as you don't mind some casualties along the way. All my fish look great, no deaths there. To me shrimp are a little more expendable but YMMV.
 
#33 ·
If there's only a little of it and your tank is otherwise healthy and well-planted, you can leave it to disintegrate on its own over a few days.

If there's a LOT of it, some attempts at mechanical removal and an extra water change or two might help the die-off from releasing too much waste into your tank.
 
#36 ·
Okay so this is what i planned;

So for my steps with my 100 gal;
H2O2
1) Remove filter media from canister filters and power back on.
2) Now add 3% H2O2, (4tbps or 59ml per 10 gals, therefore 5.9ml/gal) about 590 ml worth.
3) Let this circulate for 15 mins.
4) Terminate Treatment
5) Do a 50% water change.
6) Add Filter media again and start back filters.
Liquid CO2
7) Add liquid CO2 according to Azoo Carbon Plus (for Excel it is 5ml per 10G)
8) Done and Pray! hahaha

And this is what happened;

So for my steps with my 100 gal;
H2O2
1) Remove filter media from canister filters and power back on. Added an additional powerhead (1300L/Hr)
2) Now add 3% H2O2, (4tbps or 59ml per 10 gals, therefore 5.9ml/gal) about 590 ml worth. Actually placed 625ml.
3) Let this circulate for 15 mins.
4) Terminate Treatment
5) Do a 50% water change. Removing 50% of a 100 gal added 30 more mins.
6) Add Filter media again and start back filters.
Liquid CO2
7) Add liquid CO2 according to Azoo Carbon Plus (for Excel it is 5ml per 10G) Added 40ml of Azoo Carbon Plus, which was twice the printed value.
8) Done and Pray! hahaha

Result was the algae did not change color but it started to float off the plants. And I lost mt two ottos.
 
#37 ·
Hi Liliputman, welcome to the forum and thanks for the report! Some comments:

2) Remember actual tank water volume is always less than full tank capacity. In a well planted 100G, I'd take off 10G for substrate, another 5G for plants, and maybe more if there is significant amounts of hardscape. This applies to all chemicals, medications, etc. At 85G, the recommended H2O2 dosage would have been 501ml. Your actual dose was about 25% higher, or 7.4ml/gal.

5) Now this was a surprise. I hadn't considered the time needed to accomplish a water change in a larger tank, and this really slowed full termination of the treatment. Will be giving this some serious thought, I may need to reduce my dosage recommendation to account for variations like this.

What kind of algae was this? Sorry to hear about the two otos, but I'm glad you reported this, and everything else, in such detail.
 
#41 ·
2) Yes thats absolutely correct! :)
5) I was using a standard size hose also.

The algae was a combination of hair and beard which was over running my tank (shown below). Thank you your treatment worked and this time I did some preventive items;
- lowered my temp suing fans to 24C from 27C+
- shortened my lights from 10 hours + to 8 hours
- will add more algae fauna once my HC and HG grows a bit more.


 
#39 ·
Thanks for the tutorial. Will try this on my BBA 300L planted tank and report back. Aside from the typical GSA on the glass and a persistent BBA infestation I don't have other algae.

Taking into account the substrate and plants I will go for 1ml/L if I calculated correctly.

This will put me at 4ml/gallon. I need to make these conversions as I'm East European :)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top