Brown substance on plants

**Royston Low** · 8th Oct 2015, 13:50

Hi All,

Can anyone advise what are those brown substance on the leaves of the plants (as per the attached pictures)? This substance can be removed when i use just water and rub away.At the same time, the water of my tank starts to turn yellowish.

Thanks in advance

**Griffith DreamWalker** · 8th Oct 2015, 15:49

That's just brown algae and its pretty common in most tanks. I would advise you to get some Nerite snails to eat the algae away unless you want to go through the trouble of rubbing the leaves every week. Nerite snails DO NOT eat plants, look beautiful and are harmless. However if you have any fish that 'll eat them, get others like cherry shrimp or amano shrimp. These shrimps are not as good as nerites though as they do not eat disc algae nor that much compared to nerites. When you run out of algae for your nerites, offer them vegetables/algae wafers or they'll starve. Don't expect them to eat 'meat' as they're 'vegetarians'.

I own a nano tank with RCS, Neon Green and Amano Shrimps. Without any snails, algae still grew on the tank walls. But after adding a duo of nerites, my tank is 100% algae free. Nerite snails have different patterns and types, so you have a variety to choose from. I currently rear one of each type except for the horned Bumblebee nerite. I used to rear it though, its very useful for delicate plants as larger nerites can't eat the algae off the leaves.

These are not my nerites but are pictures that belong to others.

**Royston Low** · 8th Oct 2015, 16:02

Thanks alot. will go look into this.

**Royston Low** · 8th Oct 2015, 16:04

By the way, is this also causing my water to turn yellowish?

Another question is the leaves are all at the surface of the water. The snails are able to reach them?

**Urban Aquaria** · 9th Oct 2015, 01:10

Originally Posted by Royston Low

By the way, is this also causing my water to turn yellowish?

Water turning yellowish is usually from tannins leaching out from driftwood or soil... if you don't have those in your tank, the yellow tint could also be generated by the livestock bio-load or general accumulation of waste in the water. Its usually a sign to do water changes and clean the tank.

Originally Posted by Royston Low

Another question is the leaves are all at the surface of the water. The snails are able to reach them?

Nerite snails can climb out of water for a period of time, they are tidal snails and do crawl out of water to travel between locations (you may see them crawling out of your tank from time to time), so they will be able to access the leaves at the water surface.

Btw, do note that female nerite snails do tend to lay white eggs on tank glass, plants and hardscape which can be quite difficult to remove (you'll need to manually scrape them off). Their eggs will not hatch or develop in freshwater (they need brackish/saltwater to develop) but the eggs can be abit unsightly to some people, so do be prepared for that.

Male nerite snails do not lay any eggs, so if you happen to have those you're lucky.

**Griffith DreamWalker** · 9th Oct 2015, 22:15

What Urban said is true, however I do not believe that any nerite snails lay eggs. I have kept over 20 nerites and none have ever laid eggs in my tank. Currently my tank is egg free for the past six months... Is this what they call Super Luck?

**AQMS** · 9th Oct 2015, 22:55

Originally Posted by Griffith DreamWalker

however I do not believe that any nerite snails lay eggs.

You believed wrong my friend... wait for it....

**Griffith DreamWalker** · 11th Oct 2015, 01:28

Originally Posted by AQMS

You believed wrong my friend... wait for it....

I believe that my luck will prevail.

**Urban Aquaria** · 11th Oct 2015, 02:14

Originally Posted by Griffith DreamWalker

What Urban said is true, however I do not believe that any nerite snails lay eggs. I have kept over 20 nerites and none have ever laid eggs in my tank. Currently my tank is egg free for the past six months... Is this what they call Super Luck?

You could be very lucky, either all are males or the gender ratio is heavily skewed towards mostly males with very few females... or maybe the nerite snails are not mature yet, so its just a matter of time.

From my experience keeping nerite snails over the past few years, i do notice that the chances and rate of egg laying also depend on a number of other factors, like snail size (smaller variants like horned nerites lay less eggs and the eggs are smaller), the amount of algae food in the tank (more algae = more eggs, less algae = less eggs) and whether they are comfortable in the tank environment (if they are in acidic conditions with low minerals and their shells are eroding and they are dying off slowly, much less chance of egg laying).

So i guess its quite possible with a combination of good luck + higher male-female ratio + tank environment, you may not be plagued by the white eggs... yet.

**Griffith DreamWalker** · 12th Oct 2015, 12:18

Originally Posted by Urban Aquaria

You could be very lucky, either all are males or the gender ratio is heavily skewed towards mostly males with very few females... or maybe the nerite snails are not mature yet, so its just a matter of time.

From my experience keeping nerite snails over the past few years, i do notice that the chances and rate of egg laying also depend on a number of other factors, like snail size (smaller variants like horned nerites lay less eggs and the eggs are smaller), the amount of algae food in the tank (more algae = more eggs, less algae = less eggs) and whether they are comfortable in the tank environment (if they are in acidic conditions with low minerals and their shells are eroding and they are dying off slowly, much less chance of egg laying).

So i guess its quite possible with a combination of good luck + higher male-female ratio + tank environment, you may not be plagued by the white eggs... yet.

I keep one of each variety except for the horned nerite as they're much more sensitive to water changes than the others. My tank's environment is suitable for inverts as the PH is high and I supplement with minerals weekly. All snails have never bothered to escape from the tank, so the water's stable and clean. I can't tell the snail's age, but I tend to assume from size and shell condition. Majority of snails are bought from c328 and the people there have no idea of the snail's age. Mine should all be adults as they are around an inch in size, so should already be laying eggs if they were female.

However this new batch that I own have only been with me for sightly over two months, so maybe I'll wait longer and see if my snails'll lay eggs. One thing I have to say about nerite snails, their tentacles are very long. Mine has tentacles the length of its body. So make sure that your fish don't nip them. I know my rasaboras used to till the snail started tucking in his tentacles.