Treatment against Valonia

How to get rid of Valonia in 48 HOURS!

The H2O2 + Coral Snow method

How many times have we come up against this real plague in our tanks? When algae appear in our tanks, a sense of panic often takes hold; we try a bit of this and a bit of that, often with poor results. So let's look at an effective method against Valonia, and indeed other very annoying algal infestations.

Let's start by saying that there are various ways to get rid of Bryopsis, Derbesia and Valonia: from the natural method, adding competitors such as Mitrax sculptus for Valonia or the nudibranch Elysia crispata for the alga Bryopsis, which it loves to eat, to the more effective and final fluconazole-based product, an active ingredient that has proved very effective against infestations spread across the whole tank.

In this article we will look at a practical, quick way to wipe out algae outbreaks, such as a colony of Valonia, perhaps in a spot of the tank that the classic natural predators cannot reach.

1. 1Mitrax sculptus natural competitor for Valonia
2. 2Elysia crispata loves to eat Bryopsis
3. 3Fluconazole product for infestations across the whole tank
4. 4H2O2 + Coral Snow for outbreaks predators cannot reach

This article deals with point 4: hitting an outbreak the other remedies cannot reach.

Materials

Pasteur pipette - coral feeding pipette, 45/60 cm, to reach the most difficult spots.

H2O2 (hydrogen peroxide): in particular this brand, which is easy to find online, has no harmful additives and has been widely tested in our method.

Coral Snow Korallen Zucht (Classic, not Plus)

50/100 ml container

Dose

For every 100 litres of tank volume we can use:

• 1 ml Coral Snow
• 5 ml H2O2
• 2 ml of water from our aquarium

Once mixed we will get 8 ml of solution ready to use.

1. 1Coral Snow: 1 ml classic, not Plus
2. 2H2O2: 5 ml hydrogen peroxide without additives
3. 3Aquarium water: 2 ml taken from our tank
4. 4Ready solution: 8 ml in a 50/100 ml container

In a 300-litre tank you could use 24 ml, but for just a few spots to treat you will probably not need them.

Example: In a 300-litre tank you could therefore use 24 ml of solution; although they are well tolerated, we probably will not need them, especially if we only have a few spots in the tank to treat.

Bearing in mind that the treatment is for spot use and not for the whole aquarium, we can also use the dose for 100 litres described above, and we can even increase the peroxide dose by 50% if the algae are particularly vigorous.

Procedure

At this point we will use the solution obtained to get rid of the annoying algae as follows:

• Switch off the return and circulation pumps for 20 minutes: the calmer the water, the better.
• Draw up the prepared H2O2/Snow solution with a pipette chosen according to where the algae are (we always prefer not to put our hands in the tank), so if we have a long pipette it is better to use that rather than a Pasteur one, which will almost certainly force us to put our hands in the water.
• Squirt the solution in, taking care to get it as deep as possible, in contact with both the base of the alga and the rock, but without creating turbulence as the liquid comes out, otherwise it would be dispersed.
• Repeat the procedure the next day until the algae disappear; 3-4 applications will be enough.

1. 1Pumps off return and circulation, for 20 minutes
2. 2Long pipette better not to put your hands in the tank
3. 3Base of the alga and rock this is where the solution must go
4. 4Gentle squirt no turbulence, or it disperses

The calmer the water, the better the solution stays in contact with the alga.

After about 15 minutes we will see that the Snow has covered the alga with a whitish film; the treated area will very probably give off little oxygen bubbles, a sign that the treatment is working; all this is normal.

1. 1Whitish film the Snow has covered the alga
2. 2Oxygen bubbles a sign the treatment is working
3. 3Treated area all this is normal

The bubbles fit the chemistry: hydrogen peroxide breaks down into water and oxygen.

Sources: [6]

Conclusions

After 3-4 consecutive applications we will see the algae completely destroyed. I advise against carrying out the treatment in nutrient-poor tanks with nitrates close to zero. The compound used is very well tolerated even at higher doses; however, I always recommend trying it on a small area to get familiar with the treatment and draw your own conclusions.

There are products on the market similar to Snow but with different chemical compositions; these products might not give the desired effect, and Coral Snow Plus itself is not suitable for this treatment. I recommend using hydrogen peroxide without any added additives, like the one shown in the photo.

Article written by Tiozzo Matteo

Sources

1. WoRMS Editorial Board (2026). Mithraculus sculptus (Lamarck, 1818). World Register of Marine Species.
2. Cartaxana P., Morelli L., Cassin E., Havurinne V., Cabral M., Cruz S. (2023). Prey species and abundance affect growth and photosynthetic performance of the polyphagous sea slug Elysia crispata. Royal Society Open Science 10(8): 230810.
3. Figueiredo J., Narciso L., Turingan R., Lin J. (2008). Efficiency of using emerald crabs Mithraculus sculptus to control bubble alga Ventricaria ventricosa (syn. Valonia ventricosa) in aquaria habitats. Journal of the Marine Biological Association of the UK 88(1): 95-101.
4. U.S. National Library of Medicine (2018). Fluconazole: MedlinePlus Drug Information. MedlinePlus.
5. NIOSH (2019). NIOSH Pocket Guide to Chemical Hazards: Hydrogen peroxide. Centers for Disease Control and Prevention.
6. ATSDR (2014). Medical Management Guidelines for Hydrogen Peroxide. Centers for Disease Control and Prevention.
7. Higuchi T., Fujimura H., Arakaki T., Oomori T. (2009). The synergistic effects of hydrogen peroxide and elevated seawater temperature on the metabolic activity of the coral Galaxea fascicularis. Marine Biology 156(4): 589-596.