My caulerpa is disappearing. WHY?

mmcaleer · #1 07/11/2004, 09:19 AM

In the past few weeks my grape caulerpa has reduced in size by 75%. Why and what is happening?

90 gallon main
55 gallon sump
Ph 8.2
temp 78

Thanks,

Mike

sjvl51 · #2 07/11/2004, 01:47 PM

Caulpera needs 2 things to grow - food and light. I found when I replaced my NO flo bulbs for 2 of these bulbs - http://archive.reefcentral.com/forum...hreadid=313318 - my grape caulpera growth increased.

Macro algae feeds on nitrites, nitrates and phosphates. If your tank has very low/no levels of these 3, then the macro algae will not grow.

Vickie

mmcaleer · #3 07/11/2004, 03:12 PM

That is the exact bulb I have over mine running 7x24. Lately I have replaced my "on-loan" skimmer with a new MRC MR-2 and it is working perfectly. I think my water might be too clean now. Is there anything I should add to help it grow or just do nothing?

Thanks,

Mike

billsreef · #4 07/11/2004, 11:26 PM

Feed the tank more

Also Iron suplements might help.

beaslbob · #5 07/12/2004, 10:28 AM

the only reason any of my display macros reduced in size was they were being eaten.

If you just got a skimmer working then possibily the nutrients load went down. Even if the leavels stayed the same, there was less need for plant life to maintain those levels. That could also cause a decrease in plant life.

mmcaleer · #6 07/12/2004, 10:42 AM

When you say feed the tank more do you mean to feed the fish more? I have doubled the number of fish lately and added more shrimp but have not really increased the food too much. I have a yellow tang, blue tang, six chromis, yellow watchman gobie, two bangai cardinals, a coral beauty and a percula. Also have three cleaner shrimp and a brittle star. How much should I be feeding them. I have been giving them two frozen cubes and some Fomula Two flake. Is this enough?

Mike

billsreef · #7 07/12/2004, 11:10 AM

What are your nitrate readings? Also have you tested for phosphate? If those are undectable, than slowly start increasing the amount of food you feed the tank, that will increase the amount of, um, fertilizer

If you have detectable levels of nitrates and phosphates, than I suspect iron supplementation wil be the key.

BTW, am I correct in assuming that caulerpa in question is in your refugium and not in the main tank with the tangs?

Guy · #8 07/12/2004, 04:02 PM

Have you been harvesting your Caulerpa regularly or do you just let it grow uncontrolled?

mmcaleer · #9 07/12/2004, 07:27 PM

The caulerpa is in the sump. I have not harvested it because when I was about to it started to shrink in size. My nitrites and nitrates are zero but I have never tested for phosphates.

Mike

beaslbob · #10 07/13/2004, 09:40 AM

sounds like you need to harvest some of the caulpera.

Guy · #11 07/13/2004, 11:08 AM

What Bob said.

If you let it grow uncontrolled in a closed environment then it will run out of one or more required nutrients and crash. Many people keep several different colonies in their refugium so that the nutrient requirements overlap and they can keep more algae successfully.

Your batch should start growing soon since you've lost so much of it. If there are any older stems or leaves turning clear or white you should immediately remove them. When harvesting take the old growth and let the new parts grow. When harvesting for fish food that's when you should harvest the new growth. I believe that any pollution sequestered by the algae will be stored in the older growth. I believe this because many organisms like to eat the new growth but almost nothing will eat the older growth.

HTH
Guy

sjvl51 · #12 07/15/2004, 08:00 AM

Guy, said - "I believe this because many organisms like to eat the new growth but almost nothing will eat the older growth." Could this be because the newer growth is more tender? We prefer to eat many vegetables just as they ripen not after they have been ripe for a week or so for this same reason - more tender and more flavour.

The "pollution" you talk about. Is the nitrates and phosphates? To plants that is their food - what they use to grow. Are you talking about the toxins that some caulpera excrete to slow down/prevent the growth of other plants in their area?

I'm just trying to figure out exactly what you mean, Guy.

I agree that macro algae needs room to grow and you should harvest regularily to give it room to grow. A fast growing macro algae will consume more nitrates and phosphates than a slow growing one. Older growth does usually grow slower than new growth.

Algae needs two things to grow - food and light. It will only grow until one of it's required foods is depleted (this is the limiting factor). Billsreef's suggestion of iron is good as often iron is low in our tanks. Poor light is often the case (especially if you are using NO bulbs). NO bulbs don't have the intensity to light more than the top of the algae. PC bulbs and even your old MH (which some people use) provide a lot more intensitiy and more growth.

FWIW I have my algae grow out tank (tang heaven and ulva for tang food) on a window sill. I found that the refuge with mangroves, grape caulpera and another caulpera with my sump with chaeto was not growing nearly fast enough for the tang so I removed the tang heaven and ulva into a special tank just to grow for food. Since I have low levels of nitrates and phosphates, I think the limiting factor is the light but at the present time I can't change that.

You quite often test 0 for nitrates and phosphates because the macro algae has removed them from the water. This is what we want, but without extra nitrates and phosphates, the algae can't grow. This is why the suggestion of feeding the tank more was a good idea. Pruning also does the same thing by removing some of the algae, then there is excess nutrients again which stimulates the plants to grow.

Vickie

Guy · #13 07/15/2004, 08:30 AM

Quote:

Originally posted by sjvl51
Are you talking about the toxins that some caulpera excrete to slow down/prevent the growth of other plants in their area?

Looking at Dr. Ron's study from a couple years ago he lists several toxic substances that are found in significant quantity in Caulerpa. This list includes Alumninum, Iodine, Lead, Lithium, Zinc to name a few. I can only guess so it's just my belief that most of these harmful elements are probably stored in the old growth. My belief is based on the anecdotal evidence that my fish seem to only eat the new growth when given a choice.