diatom?

[seakwon]

so i have recently had a problem with algae, i have been through a lot of these forums lately trying to get some answers.

nobody has made one that has worked so far so now i am thinking outside the box. if everything is fine with parameters, can i try a diatom filter to clear it up? are they worth the investment?

also i heard of a way to make your own diatom filter, it involves a back filter and the diatomatious (?) powder. can i use the stuff i use for my pool, or are the powders totally different?

if anyone else has any other ideas i am open as of this point. any help would be appreciated.

[pjf]

Here is a link to a WetWebMedia FAQ about "Diatom/aceous Filtration for Marine Systems:" http://www.wetwebmedia.com/diatomfltfaqs.htm.

I understand that diatomaceous earth filter media will remove particulate matter and "polish" the water but I am not aware that it removes phosphates, nitrates, nitrites and ammonia that algae feed on.

As for unwanted algae, I'm using granular ferric oxide (GFO) to remove phosphate that is utilized by algae. I place the GFO in my granular activated carbon (GAC) reactor. If that doesn't work, I plan to raise the magnesium level to 1500-1600 ppm and the pH to 8.3-8.5 to combat bryopsis algae.

Freshwater aquarium owners claim that diatom filters polish their water to the point that the fish seem to be "floating in air." Please let me know if diatom filtration has the same effect on reef aquariums.

[seakwon]

can algae be caused by anything besides phosphate? i dont have any of that so i dont know whats wrong. i tested the water at the lfs they said nothing is wrong at all with my parameters....nothing! i guess

[pjf]

Randy Holmes-Farley’s article, "Phosphate and the Reef Aquarium" (http://reefkeeping.com/issues/2006-09/rhf/index.php), has some interesting quotes:

Typical ocean surface phosphate concentrations are very low by reefkeeping standards, sometimes as low as 0.005 ppm.

At concentrations below about 0.03 ppm, the growth rate of many phytoplankton species depends on the phosphate concentration (assuming that something else, such as nitrogen or iron, is not limiting their growth). Above this level, many organisms' growth rate is independent of phosphate concentration. So, to deter algal growth by controlling phosphate, aquarists need to keep the phosphate levels quite low.

The article lists a number of remedies to reduce phosphate levels.

What phosphate test kit is your LFS using? Measuring such low levels of phosphate is not easy. I have 4 phosphate test kits. On the same test sample, their results are all over the map. Two of them tend to under report phosphate levels. One popular kit is prone to giving false negatives. The two kits that I trust most cost over $50 each and even they don't always agree.

A lights out period may be worth a try: http://www.reefcentral.com/forums/showthread.php?s=&threadid=1078532.

[seakwon]

Thanks PJF that is a very helpfull sight on phosphates. i have cut down the time of lighting to only 6 hours now. i think the lfs was using salifert testing.... dont rem. though. i just dont know what to do here....

[scotmc]

I have found doing 10% water changes daily will get rid of the problem. Also running phosban will help reduce the daily water changes.

[hebygb]

water changes, use RO/DI

By any chance did this bloom occur after moving substrate from one tank to another tank? This is often the case because you "turned" your substrate upside down. and exposed all this bacteria to the surface. exposing it to nutrients, light etc.

Its not the same as when a sand sifter digs in, the tanks biology can handle that...

[pjf]

Here's another tibit from Randy's article (http://reefkeeping.com/issues/2006-09/rhf/index.php):

Flake fish food is typically about 1% phosphorus (3% phosphate equivalent) by weight (and many products have such phosphorus data on their labels). Consequently, if five grams of flake food is added to a 100-gallon aquarium, there is the potential for the inorganic orthophosphate level to be raised by 0.4 ppm in that SINGLE FEEDING!