White spots on tank wall

[duster]

I have a 12g w/ LR, running for six months, stocked for four months w/ three little fish, two shrimp, and several crabs and snails. About one or two months ago, little white spots began appearing on the back wall and filter components. The spots are small and hard, with some variation in size. I scraped them off once, and a day or two later numerous spots were back. I've let it go for a month now, and the number of spots has increased of course, but isn't out of control. What are these? Calcium deposits? Eggs? Because of the large bio-load and no protein skimmer, I do very frequent water changes (1.5g every 3-4 days). Could it be an excess of calcium or trace elements from the new saltwater being introduced every few days? I do not supplement calcium or anything else.

[Poseidon]

It could be coralline Algae starting to take hold. OR it could be a calcium based worm or other such critter. I would let them go for a while and see if it turns purple/pink, that is the Coralline algae. Either way I suspect that it is harmless.

[duster]

Thanks Poseidon
I got the same answer at another forum and it makes sense. I guess I didn't consider it being coralline algae because I had only heard and read about it being purple, pink, orange, and green. I've got dark purple and pink coralline algae developing nicely on my LR, so it seemed weird that the white stuff only grows on my back wall. Will coralline algae change color? The algae on my LR is spreading in color, without being white first.

[Ninong]

Thanks Poseidon
I got the same answer at another forum and it makes sense. I guess I didn't consider it being coralline algae because I had only heard and read about it being purple, pink, orange, and green. I've got dark purple and pink coralline algae developing nicely on my LR, so it seemed weird that the white stuff only grows on my back wall. Will coralline algae change color? The algae on my LR is spreading in color, without being white first.

When I neglect my front glass for two or three weeks -- like when I went to California in October -- the coralline algae that starts to form is purple no matter how tiny the little spots are. I have never had corraline algae in my tank that started out as any other color no matter where it formed.

If the small white spots appear to be spiral shaped, they could be calcareous worms. But the spiral shape is obvious even to the naked eye, so you would have said something about that already and you didn't. So that leaves snail eggs as the most likely explanation. If you are able to remove a few of these white spots with a razor blade, you would be able to examine them more closely. If any of them formed on the front glass, you could examine them with a magnifying glass without disturbing them.

What sort of snails do you have in your tank? You can rule out Cerith eggs because they lay their eggs in spiral strands that are tied together rather than individual egg capsules. And Cerith egg strands will blow off the walls of the tank within a couple of days anyway. Nerite snails lay individual egg cases that look a lot like white sesame seeds but in my tank, they lay them only on the live rock. Nassarius snails do lay egg capsules that harden on the substrattum shortly after they are extruded. Actually, Nassarius eggs are fertilized internally and then the fertilized eggs are enclosed in a translucent capsule that is extruded. There are usually four or five embryos in each capsule. I have been able to make these out using a magnifying glass when I allowed some to remain on the glass. The embryos hatch in a few days into veliger larvae which are no doubt consumed by the tank's other inhabitants. These cannot reproduce in our tanks because the planktotrophic stage lasts for a few weeks!

I have another snail that lays eggs that are encased in similar capsules. I don't even know the correct name of this snail for certain but it was sold to me by IPSF as Strombus maculatus. It's NOT S. maculatus but it is a cute little snail that reproduces readily in aquaria. I have another small snail that I wish I didn't have that reproduces like wildfire in my tank but I'm not sure of its reproduction mode because I haven't bothered to look it up yet. It's a tiny trochid that gets no more than about 5 mm across when fully grown. I have those in the hundreds even though I never actually paid for them. They came in as hitchhikers several months back and I have been unable to erradicate them. They are actually quite pretty under a magnifying glass but enough is enough and too much is too much. I have way too much! They displace other snails that I paid good money for by eating all the available food. Within a few months after these little pests made their presence known, my thriving population of Stomatella varia was history.

[Poseidon]

My coralline seems to start in very small patches and is a very very pale pink. Almost white. But I think snail eggs are probably a better explanation, especially if they dissappear on their own.

[Ninong]

My coralline seems to start in very small patches and is a very very pale pink. Almost white. But I think snail eggs are probably a better explanation, especially if they dissappear on their own.

Coralline in my tank starts out as a microscopic dot that gets gradually larger. It is purple in color from the time it is visible to the naked eye. Dots that are near each other will merge eventually to form small patches but originally they were tiny dots the size of pinheads -- lavendar/purple pinheads!

[duster]

Up until the writing of this reply, I had two types of snails: (3) Super Tongan
Nassarius (Nassarius distorus) and a Top Crown Astrea (Astrea undoza). However, I just removed the dead Astrea. He spent his time on the rock or the substrate instead of the back wall, which is where I needed him. I clean my three viewing panels weekly, but the back wall is much harder to clean so I was going to rely on the friggin' huge Astrea to keep it clean, but he never touched it and finally died. I'm not concerned though, as I believe it was starvation or old age. I also just cleaned and scraped the back wall, so if the white spots reappear, it would have to be coralline algae or Nassarius eggs.

[newbie]

I seem to also have a similar problem, but my little white spots look like small swirls, circles. I have noticed them pop up over the past couple days. Now one of my clown's has white spots on him also. He is also not swimming well. My tank is a 40l with 10 asterea snails, 8 snail that live in the sand, 2 conch, 1 Coral Beauty Angel, 1 Y Tang, 2 clowns, and a Goby. ANY ideas?

[Ninong]

I seem to also have a similar problem, but my little white spots look like small swirls, circles.

Harmless. No problem.

Now one of my clown's has white spots on him also. He is also not swimming well.

This could be bad news! It might be marine ich (Cryptocaryon irritans). How long have you had the yellow tang? And is that a typo or did you say this is a 40 liter tank? (P.S. -- Nevermind. I just checked your profile and you live in N.Y., so you probably mean a 40 long, as in 40 gallons. Still much too small for a tang.)

Terry B's ich article:

Part I: http://www.advancedaquarist.com/issu...2003/mini1.htm

Part II: http://www.advancedaquarist.com/issu...2003/mini2.htm

Part III: http://www.advancedaquarist.com/issu...2004/mini3.htm

Part IV: http://www.advancedaquarist.com/issu...2004/mini4.htm

Part V: http://www.advancedaquarist.com/issu...2004/mini5.htm

[newbie]

Yes it is a 40 gallon long. I have had the tang 2 maybe 3 weeks. He is small though.

As for the ich, I am very limited on another tank to put them in. Would doing a 25% water change on a daily basis over the next week help? I just don't have another setup to move everything into.

[Ninong]

Yes it is a 40 gallon long. I have had the tang 2 maybe 3 weeks. He is small though.

If you actually do have ich, there is a good chance it came in on your yellow tang.

As for the ich, I am very limited on another tank to put them in. Would doing a 25% water change on a daily basis over the next week help?

No. You really need to read the articles I linked above. All of your questions will be answered. Sorry.