The Inevitable Algae Bloom.

[Hypostomus]

Okay, I figured this would happen. On a 20g saltwater reef tank my parents have reported the first signs of what will likely be a torrent of algae. We have 130 watt PCs which are helping the stuff along. I'm going to be saving up so we can get a RO filter and an AquaC Remora or a CPR BakPak 2R skimmer to make sure the water is pure, but it's unlikely any of that will happen till this summer. Therefore, I advised my parents to go to the LFS and ask if they sold RO water (I know they use it on their tanks there) and stock up for water changes. We have a clean-up crew but they aren't making a dent, apparently.

Anything else that can be done in the meantime? I'll ask my mother to take a nitrate reading, but for as long as I was maintaining the tank over Spring Break they were at a consistent 0, FYI.

The clean-up crew (as far as algae goes) consists of a baker's dozen of blue-leg hermit crabs, and a dozen astrea snails. They're all very tiny and not of much use yet. Occasionally the LFS has a blue tuxedo urchin on sale, but I doubt one creature is going to solve the problem. So let me refine my question: anything as far as water quality and the tank set-up that we can do? :) The algae I saw building was hair algae.

EDIT: I thought I would add a picture of the tank from when I was there. We had moderate algae at that point, so I'm assuming that now it's more dense.

[jackdp]

How old is the tank. Its not uncommon for newer tanks to go through some algae blooms as the tank matures. For the most part I would find the food for the algae. If its hair algae, check the tank for nitrates and moreso phoshpates. If you find any phosphates then that's the problem. I assume you are using tapwater based on your post. If that's the case then that could be your problem. Have your parents look around for machines outside or inside of grocery stores or beverage stores anywhere. They will allow you to fill your container with filtered water. This is usually RO/DI water and is great for aquariums. Verify that the water is RO filtered and you're good to go. It usually sells for about .25/gal. Mix up some SW and test the fresh SW for phosphates, nitrates etc just to be sure its a good source and keep an eye on tank levels.

[Anemoneman]

Regularly harvested macroalga will stem the growth of hair algae.
Try and get some grape caulerpa established and harvest a handful when it gets large to export nutrients. It will out compete the hair algae and you will be able to get it under control.

[Hypostomus]

The tank is about 2.5 months old at this point. I was assuming it was the phosphates in the tap water because the nitrates are at 0. Are there any special requirements for grape caulerpa or a particular place I should set it in the aquarium? I was thinking that we have one slightly stagnant corner that it would do well in without taking light from the corals.

[Anemoneman]

Good strong lighting will encourage it to grow. It does well in a quiet area of my tank. There are no special requirements other than lights. Give it time to catch up and your hair algae will be history.