5 WAYS TO GET RID OF BRYOPSIS ALGAE IN REEF TANKS

5 measures against Bryopsis algae in the saltwater aquarium

It is really particularly exciting when you can watch the first algae and sponges develop on your live rocks during the running-in phase of your saltwater aquarium.

However, you should look closely, because sometimes things grow there that no saltwater aquarist wants in their tank. One of these pests is the green algae Bryopsis.

The algae itself has a hair- or feather-like growth form, with the individual branches arranged in tufts. Bryopsis grows incredibly quickly and can quickly become a real nuisance in a reef aquarium.

In the following report, we will show you how you can prevent the outbreak of Bryopsis and what measures you should take if the algae have already spread in your aquarium.

1. Manually removing the algae

As soon as you start to worry that some tufts of Bryopsis might have developed in your tank, you should immediately grab a pair of tweezers and remove the green algae with determination. You can then check afterwards whether it is actually Bryopsis. If your fears turn out to be true, you should observe the situation very closely and remove the newly grown tufts again if necessary.

2. Removal of heavily overgrown furnishings

If you can't get the problem under control by just pulling it out, you should remove the affected decorative material from your tank as quickly as possible. Bryopsis spreads really quickly, no, very quickly! So you shouldn't hesitate for long before your entire stone structure is overgrown by the algae.

It is best to remove individual stones completely; affected areas of larger decorative elements should be cut off generously using a hammer and chisel. It is best to remove the affected elements from the tank for a short time. You should make sure that the glass of your aquarium is not damaged during the process.

3. Natural predators

Luckily, Mother Nature has a solution for pretty much every problem, because Bryopsis algae also has some natural predators. Here are the little creatures that could help you get the problem under control:

• Percnon gibbesi (rock crab, algae-eating crab)

• Elysia crispata (cauliflower snail)

• Turbo fluctosus (Mexican turbo snail)

• Siganus vulpinus (foxface)

Since E. crispata is regularly offered for sale as a captive-bred fish, you should try to purchase captive-bred fish. Before purchasing the other predators mentioned, you should definitely find out about their care requirements. Unfortunately, there is no 100% guarantee that the animals will actually eat Bryopsis algae.

4. Increase magnesium concentration

Another way to get your Bryopsis problem under control is to increase the magnesium concentration.

Some saltwater aquarists have reported a reduction in algae after briefly increasing the magnesium level in their tanks to 1600 to 2000 mg/l. Under normal conditions, this level should be in the range of 1250 to 1350 mg/l.

To increase your magnesium concentration, we recommend preparing a stock solution using magnesium chloride hexahydrate (MgCl ₂ *6 H ₂ O) or using commercially available ready-made products.

To prepare the stock solution, dissolve 836 grams of magnesium hexahydrate in 1 liter of osmosis water. Adding one milliliter of this stock solution increases the magnesium concentration by 1 mg/l per 100 liters of aquarium water. If you want to increase the magnesium content in your 300-liter reef aquarium from 1300 to 1600 mg/l, you need to add a total of 900 ml of the stock solution.

However, you should spread the addition over several days, as some reef organisms are very sensitive to abrupt changes in environmental conditions. Also keep an eye on the salinity during the addition and take necessary regulatory action.

5. The chemical club: Flucanozol

If you cannot get your Bryopsis infestation under control with the measures mentioned above, you can still play one last trump card – fluconazole.

Fluconazole is an antimycete that is actually used to treat fungal infections in humans. However, the drug is prescription-only in Germany and you must have it prescribed by a doctor.

The use of fluconazole in the fight against Bryopsis is "relatively" new and comes from the USA. Although the method promises very good chances of success and so far there are few reports of negative side effects, you should still be careful and keep a close eye on your animals during treatment.

During treatment, you should disconnect your algae filter or refugium from the main system, do not use activated carbon, do not carry out any water changes, switch off the UV filter and remove the skimmer pot.

The dosage is 5 mg of fluconazole per 1 liter of aquarium water. You should weigh the contents of the tablets using a precision scale. For example, if you want to treat your 300 liter aquarium with the preparation, you will need a total of 1500 mg of fluconazole. You should dissolve the granules in a little water before adding them. The dosage is a one-time dose.

The treatment lasts about 14 days and is over when all Bryopsis algae have disappeared. Afterwards, you should carry out a generous water change, reinstall the skimmer pot and filter through activated carbon.

A product available for purchase in some EU countries is called FluxRx and is sold by the company Blue Life. It also contains flucanozole. Follow the manufacturer's instructions when using this product.

We hope we were able to help you with these tips and wish you much success in the fight against your Bryopsis infestation!