Plagued by unknown brown slime

[TheNaturalAquarist]

Hi everyone,

I've got a 90 litre tank that's been set up for over 2 years and I've always struggled with an unidentified brown slime/algae.

I had an initial outbreak soon after the usual diatom phase, but it then suddenly disappeared after I treated the tank for an outbreak of cyanobacteria using Ultralife's Blue Green Slime Remover. I put this down to a coincidence and assumed that it must have been the remainder of the diatoms needing to burn out.

Cut to a year and a bit later and it comes back worse than before, with it smothering most of the plants and either slowing growth or killing them off. I've recently tried another cyanobacteria treatment which did knock it back, but it's starting to come back again only a few weeks later.

Does anyone know what it could be or how to treat it? It's not dusty or easy to brush off like diatoms but nerite snails do try to eat it (although very slowly and not enough to make a dent in it), so I'm not sure what I'm dealing with. I've also stopped dosing fertilisers as I couldn't tell if this was encouraging the algae or not.

Specs

Tank: 90 litre
Filter: Eheim BioPower 200
Temperature: 23 degrees
Light: Chihiros WRGB 2 Slim*

*light was only added last week after the algae started coming back. Previously used an All Pond Solutions PLED

Thanks!

This was the worst it got to...

Original tank during it's healthy phase

The tank today (algae starting to come back)

 

[dw1305]

Hi all,
Welcome to UKAPS.

It's not dusty or easy to brush off like diatoms but nerite snails do try to eat it (although very slowly and not enough to make a dent in it), so I'm not sure what I'm dealing with

Yes, it looks like diatoms, not much else is <"that colour">.

but nerite snails do try to eat it

I'm going to tell you snails <"are your friends">, and that the "pest snail" narrative is spread by <"unscrupulous vendors"> of products you have to buy, they just don't want you to acquire a "product" that performs that duty for free.

I'd really recommend <"Red Ramshorn Snails"> (Planorbella duryi). I have a range of <"tank janitors"> in all the tanks.

I've also stopped dosing fertilisers as I couldn't tell if this was encouraging the algae or not.

I'd start dosing again, I see you have a floating plant (which I'm going to guess is Salvinia) and you can use a floating plant (not CO2 or light limited) as an indication of when to add nutrients (have a look for <"Duckweed Index">) & have a look at <"Brown fuzzy algae, unhealthy plants and dosing questions">.

cheers Darrel

 

[TheNaturalAquarist]

Thanks Darrel!

There are 4 nerites and around 7 amano shrimp in the tank but they can't compete with how quickly it spreads. I've considered ramshorn snails but am concerned about how quickly they'll breed given the amount of the stuff that keeps growing.

I'd start dosing again, I see you have a floating plant (which I'm going to guess is Salvinia) and you can use a floating plant (not CO2 or light limited) as an indication of when to add nutrients (have a look for <"Duckweed Index">) & have a look at <"Brown fuzzy algae, unhealthy plants and dosing questions">.

Interesting you mention the salvinia. Whenever the algae starts coming back I find that almost all plant growth grinds to a halt, including the salvinia. Some of it has started going brown and getting holes in it, but I assumed that was just it dying off? Do you happen to know what could be going on?

I've got Tropica Premium and Specialised to hand that I can use.

 

[TheNaturalAquarist]

Hi all,
Welcome to UKAPS.

Yes, it looks like diatoms, not much else is <"that colour">.

I'm going to tell you snails <"are your friends">, and that the "pest snail" narrative is spread by <"unscrupulous vendors"> of products you have to buy, they just don't want you to acquire a "product" that performs that duty for free.

I'd really recommend <"Red Ramshorn Snails"> (Planorbella duryi). I have a range of <"tank janitors"> in all the tanks.

I'd start dosing again, I see you have a floating plant (which I'm going to guess is Salvinia) and you can use a floating plant (not CO2 or light limited) as an indication of when to add nutrients (have a look for <"Duckweed Index">) & have a look at <"Brown fuzzy algae, unhealthy plants and dosing questions">.

cheers Darrel

Also forgot to mention that I have a venturi valve on the skimmer, so I wonder if the bubbles could be impacting the salvina growth?

 

[dw1305]

Hi all,
I should have said nice tank.

I've considered ramshorn snails but am concerned about how quickly they'll breed given the amount of the stuff that keeps growing.

Honestly snails <"are your friend">, if you need to thin them out? It is really easy with a lettuce leaf in a net, snail trap from JBL, Ista etc.

Interesting you mention the salvinia. Whenever the algae starts coming back I find that almost all plant growth grinds to a halt, including the salvinia. Some of it has started going brown and getting holes in it, but I assumed that was just it dying off? Do you happen to know what could be going on?

Yes, that is <"definitely not happy">, that is the great thing about floating plants, they aren't light or CO2 limited so that only leaves the mineral nutrients . Because it is the older leaves (that have browned) it is likely to be a <"mobile nutrient">, unfortunately that is the majority of nutrients. If you have very hard tap water (and I'll guess you do, because you live in London) it might be worth trying adding a little extra magnesium sulphate heptahydrate (<"Epsom Salts">) and a <"different chelator"> for iron (Fe)

I've got Tropica Premium and Specialised to hand that I can use.

Try a bit more "Tropica Specialised". The "Tropica Premium" doesn't contain any nitrogen (N) or phosphorus (P), which are two of the macro-nutrients that plants need most of. There is nothing wrong with <"Tropica Specialised">, it is just an <"expensive option">.

Also forgot to mention that I have a venturi valve on the skimmer, so I wonder if the bubbles could be impacting the salvina growth?

Possibly, but I'd guess that isn't the problem. I run a <"venturi on my tanks">.

cheers Darrel

 

[TheNaturalAquarist]

Thanks Darrel!

If you have very hard tap water (and I'll guess you do, because you live in London) it might be worth trying adding a little extra magnesium sulphate heptahydrate (<"Epsom Salts">) and a <"different chelator"> for iron (Fe)

I do have hard water, but don't have any individual fertilisers. I'll start dosing Tropica Specialised for a week or so and see where that gets me before considering ramshorns. I'd love to have a group of otocinclus but unfortunately they don't do well in hard water.

I'm assuming adding more nerite snails in though won't make much of a change? Also, could there be anything in the algae responding to the cyano treatment?

 

[dw1305]

Hi all,

I'm assuming adding more nerite snails in though won't make much of a change?

I've <"not kept them"> (I'm a rainwater user) but I think they mainly clean the hard scape. Also I'm <"too mean to spend money"> on something that won't breed in the tank.

Also, could there be anything in the algae responding to the cyano treatment?

Probably not, but I'm not a fan of most chemical treatments (I have used <"Panacur etc">.), so I don't have much experience with them.

I'll start dosing Tropica Specialised for a week or so

Give it a couple of weeks, with mobile nutrients you should get a <"fairly quick response">, but with the non-mobile nutrients you only see a <"response in new leaves"> that have grown once that nutrient is available.

cheers Darrel

 

[sparkyweasel]

I'd love to have a group of otocinclus but unfortunately they don't do well in hard water.

The are quite adaptable.The real problem is finding healthy stock to start with. They don't like the standard importing and shipping methods.

 

[G H Nelson]

Thanks Darrel!
I do have hard water, but don't have any individual fertilisers.

Just do 25% water changes twice or three times a week....There will be Nitrate in the tapwater....plus other nutrients!
Reducing the light intensity and duration will also help.

 

[TheNaturalAquarist]

The are quite adaptable.The real problem is finding healthy stock to start with. They don't like the standard importing and shipping methods.

I might be able to source some, but my concern is that my water is around 16gH and 20kH and I'm not sure how well they'll do under those conditions.

Just do 25% water changes twice or three times a week....There will be Nitrate in the tapwater....plus other nutrients!
Reducing the light intensity and duration will also help.

I was doing 50-75% water changes several times a week but it didn't really help with this so I returned to my usual of around 75% once a week. I also only had my lights on for 5 hours but that didn't help either. The only thing that helped was the cyano treatment but I can't rely on that long-term and it hasn't been as effective this time round.

 

[G H Nelson]

Hi
I would still do 25% water changes my experience is that the aquarium response better doing that regime!
Adding Epsom salt will help, as Darrel stated.
Your quite low in plant mass.
Purchase some fast growing stems and use them as the article below.

Using stem plants as a filtering aid at Start Up!

The subject of using fast-growing stem plants as part of a filtering aid has cropped up a few times recently. This idea has been around for a long time so not new, it has benefits especially for a new set - up. I try and cover at least 50% of the water surface minimum. 1. Improves water...

www.ukaps.org

hoggie

 

[TheNaturalAquarist]

Hi
I would still do 25% water changes my experience is that the aquarium response better doing that regime!
Adding Epsom salt will help, as Darrel stated.
Your quite low in plant mass.
Purchase some fast growing stems and use them as the article below.

Using stem plants as a filtering aid at Start Up!

The subject of using fast-growing stem plants as part of a filtering aid has cropped up a few times recently. This idea has been around for a long time so not new, it has benefits especially for a new set - up. I try and cover at least 50% of the water surface minimum. 1. Improves water...

www.ukaps.org

hoggie

Would you do this weekly or still every other day? I used to have a load of lindernia rotundifolia in the back section which ended up dying off after the second outbreak of this algae. I've tried replacing twice with rotala rotundifolia and limnophila sessiliflora, both of which I still have remaining bits of, but they're not growing fast enough to compete with the algae.

I'll take a look into epsom salts. How much would I need to dose?

 

[G H Nelson]

Twice a week minimum.
1/4 Teaspoon....after water change.
Ive never had great success with Rotala sp in hard tap water without using Co2 and high lighting!
Float the limnophila sessiliflora on the surface monitor its growth.
I'm sure you will need Potassium as the Java fern look a tad unhappy!

 

[TheNaturalAquarist]

Twice a week minimum.
1/4 Teaspoon....after water change.
Ive never had great success with Rotala sp in hard tap water without using Co2 and high lighting!
Float the limnophila sessiliflora on the surface monitor its growth.
I'm sure you will need Potassium as the Java fern look a tad unhappy!

Thanks! Will see if I can get hold of some.

The Rotala and Limnophila started growing once the algae died back but they've slowed again now it's returned.

I've started dosing Tropica Specialised Nutriton, so hopefully that'll help kick-start the Java Fern again.

 

[TheNaturalAquarist]

1/4 Teaspoon....after water change.

Just to check, I assume any unscented epsom salts are alright?
Amazon product ASIN B06WRP671T

 

[G H Nelson]

States the Scent is "Fresh" what ever that means?
You can purchase Epsom salt at the Chemist!
Amazon product ASIN B006MXL1J8

 

[dw1305]

Hi all,

I also only had my lights on for 5 hours but that didn't help either.

That definitely isn't going to help. I would never <"go below eight hours light"> (which is still sixteen hours of darkness) and I usually <"have twelve hours">.

I'll take a look into epsom salts. How much would I need to dose?

They are ~10% magnesium (Mg), and you would want about 5 mg / L (ppm) Mg. The tank is 90 litres, so for a quick bit guestimation I'm going to call that 100 litres.

One gram contains 1000 mg, and of that 1000 mg, 100 mg (~10%) is magnesium (Mg). One gram of Epsom Salts addd 1 ppm to 100 litres of tank water and therefore 0.9 g adds 1 ppm to 90 litres. We want 5 ppm (5 x 0.9), so that is ~4.5 g of "Epsom Salts".

You can check this from <"Nutrient Dosing Calculator"> (below)

Just to check, I assume any unscented epsom salts are alright?

Yes, that one is fine.

cheers Darrel