Algae Problems

[Palster]

First off let me start by saying I am somewhat new to saltwater fish keeping so I this is kind of a newbie question. I am currently experiencing an algae bloom in my tank. I have two types on nuisance algae. One is what I believe to be green hair algae. The other is what I believe to be purple slime algae. Ammonia is 0, nitrites are 0, PH is 8.3 and the test kit is showing low levels of Nitrate (near 0) however I tend not to believe this as this test kit is old and I suspect inaccurate. The tank is 90 gallons with a sump and approx. 90 lbs of live rock. All the fish in the tank are healthy. The tank has been running for about 3 months but all of the live rock and live sand used during the setup were from an established system (most of it was from my 50 gallon which had been running for quite some time with some additional fully cured live rock added as well). I had been using a Prism protein skimmer ,which did not seem to working well, up until a few days ago when I switched to a Berlin skimmer. I have also been using tap water as I do not have a R/O unit for purifying the water. From what I have read I suspect the problem is a nitrate and phosphate issue caused by both the inefficient skimmer I had been running and the tap water. I think I have solved the one problem of the skimmer as the Berlin skimmer seams to be working well as of today. My question is if I was to go to the purified water store and purchase bottled water in 5 gallon containers (I have lots of 5 gallon jugs which I can fill for 2 bucks apiece) would this help with the water quality (the purified water store uses a reverse osmosis system) and also how much water should I be changing with each water change (I was thinking of doing 20 gallons). This would be a band aid solution until I purchase a reverse osmosis system. I live in a rural area and we have a small community water system where the water is pumped out of a creek so I have no idea what the water quality is like.

[christyf5]

Likely the problems do stem from your tap water. RODI is definitely the way to go and even if you can get your hands on some water from the purified water store it will definitely reduce the nutrients in the tapwater that are possibly fuelling your algae. In the meantime, the 20 gallon water changes are definitely a good place to start. If you can afford to do larger water changes they will certainly help as well, that way you can dilute out as much of the nutrients as possible.

What do you have for circulation? The purple slime algae seems to like areas with less water movement.

[danny zubot]

the 20 gallon water changes are definitely a good place to start.

I would agree if you were replacing the water with RO/DI, but changing your water with tap water is only replacing the possible causes of the algae bloom, IE Phosphates. In many places there are high PO4 levels. Try using a PO4 sponge (remover)

Of course every new tank experiences some form of bloom.

[DanG]

One thing that can lead to algae (in addition to what was mentioned above) is low alkalinity.

[Palster]

I am doing a 25 gallon water change tomorrow morning with R/O water (just finished mixing the water) As for circulation I have a pump in the sump moving about 700 gph after elevation loss is factored in and I also have a fairly large power head in the tank as well. The purple slime algae does seem to collect in the areas with the least water movement though. Should I be able to get a PO4 sponge at most aquarium stores?

[seashells]

Reasonably accurate test kits are either Salifert or Hach. RO/DI water is the way to go. An inexpensive RO/DI unit is AquaSafe which can be found on ebay. It's made in North Vancouver. You should test for phosphates. Also the amount and type of food you feed to your fish can put phosphates into the system. Using a phosban reactor and rowaphos works good for the phosphates. Nitrates are probably better reduced by frequent water changes.

Doug

[Palster]

Thanks for the tip on the Aqua Safe R/O units. I managed to find them on Ebay and they are much cheaper than I expected. I plan on ordering one soon.