Philosophos

Quite frankly, I've never seen evidence that non-limiting nutrients and CO2 for a given light level induces algae in any way. You've never offered concrete evidence for your conjecture that it does, and I'd like you to do so before you continue on with this concept. So far, Diana's book and Tom Barr's work both disagree with you, along side a vast quantity of aquariums. With the exception of PO4, even Paul Sears work doesn't agree with you. It really would be nice to see some real evidence here.

The concept of light stimulating various forms of algae is nothing new. Various forms of algae are better photosynthesizers than others; they can pump out more effective pigments and sometimes adapt to match even a specific spectrum better. I use BBA as an example because it is the best one available; it will change between various forms of chlorophyll and phycoerythrin (use wikipedia if you want sources, or any basic resource for red algae) to match more efficient methods of uptake. It will thrive under higher levels of light than other algae common to the home aquarium.

How is it advantageous for a class of algae that includes heterotrophs often relying on more obscure pigments to actually compete in high light, when both those factors push towards low light? Germination signaling is a concept that shows promise under these conditions. If you look at the life cycle of many diatoms, high light actually induces a suspended stage of growth under high current; the algae dwells in the column where it is more easily removed by mechanical filtration. Mucilage production would be pointless at this stage; it would cause the algae to clump and fall rather than taking advantage of the high light in a suspended state. No mucilage means no attachment.

Audouinella is a red algae; no relation to brown diatomacious algae.


Read the paper again; this was a study for a freshwater species, it has nothing to do with the hobby.

Reefs run no higher than what I do on CO2 tanks; 10-15x turnover per hour. Sometimes a bit more.

mudboots

Just to update, the tank turned green while I was out so there went my reason for removing the water movement. I put it back on and the fish are happy again. I'm guessing the main issue with the onset of green water and other algae was that in my absence, with an increase in CO2 (no water movement plus changed light schedule to allow build up in afternoon) the plants went through the available nutrients in no time, leaving the algae to outcompete it in CO2 utilization. I have started EI dosing potassium and phosphate (K2SO4 and KH2PO4) at half the recommended dose (.25 tsp 3x per week in a 125 of each). So far this plus feeding the fish seems to be having a positve impact in the aquarium. I think that if I ever move I'm going to do things quite differently.

prBrianpr

Well I dont read all of the replies. i only can say that if you use a powerhead with a prefilter in a Day you can catch all the debris. Then take it out and use the Koralia. Problem Solved.

mudboots

I thought about that, but with the onset of the green water that filter would clog every hour or less (tried it last time I had an outbreak). Just as much a pain, but less expense, will be water changes. I'm going to do 50% every day or two until it clears back up. It was there recently, so no reason it can't go back. Poor Melinda said if I dont get it cleared in two weeks she's going to buy a CO2 system herself, replace the lights I just removed, start dosing fertz and turn it into a high-tech propagation tank...over my Pea Soup!!! Hah!

mudboots

I realize this post has gotten dusty and served its purpose (for me anyway), but I thought I ought to mention something based on Dan's comment above. After an incident where I took a bit of sarcastic humor as solid advice (details are in the journals forum "Mudboots' 125 NPT" thread), I got back to the basics out of necessity. I decided to go back to what had always worked to begin with, before I started trying to figure everything out, and Ta-Dah...it's a happy day. What I had originally started with on day one was (I just realized this after reviewing this post to see where I've been, so to speak) exactly what Dan had mentioned above. I never had problems until I started messing with things. Now that I've gone back to low-to-no flow, lower light for CO2 saturation, no ANYTHING other than heaters and feeding the fish, the plants are, you guessed it, growing, and very well at that. While I lack enough light for super-fast growth, I have sufficient light for what I'm willing to add as inputs to get my plants to grow well, and the water is finally clear (latest pics on my journals thread do not yet reflect this as those are a few days old already), and the fish seem happy, so all good as far as I can tell.

What does all this mean to anyone else? Probably very little. All of our systems are so unique that it's nearly impossible to replicate another one in a different area (water parameters, temperatures, plant species, fish species, you name it...) mostly because we all have differing goals. My goal has been to have a large NPT with nothing plugged in but the lights. I had to learn that plants tend to like it warmer than the 50-60's, so I'm cool with adding heaters to my list of appliances. But I had to give Dan props for offering on more than one occasion some solid advice that I pretty much ignored. I think the most challenging issue was trying to figure out how much T5-HO light was too much or too little on a 125 gallon tank (turns out that you can get by with surprisingly low watts per gallon and still get sufficient PAR values on a low-med light El Natural set up).

'preciate it,

Darren

Philosophos

Thanks Darren, your post means a lot to me.

I think your experience is quite valuable, because others have shared it in general principle. Nutrients are relatively easy to nail down, but the nuances of light/CO2/flow interactions are something that the whole hobby is struggling with to one extent or other.

I'm glad things are recovering for you. I'm at the opposite end of the spectrum with one tank right now; everything is as you and I have tried, but a new bulb is putting out its early life excessive burst. Needless to say there's algae everywhere, but if the principles hold then 100 hours or so of running the bulb should get rid of the problem.

mudboots

My pleasure. BTW - it's funny you mention the new light. Davemonkey and I had a conversation about this because he had a similar issue. He found a cure by placing thin cardboard strips across the top of his tank to block out about 30% of the light until his floaters fill in a little bit. He said the results were noticeable pretty quick.

Philosophos

Thanks, I may try that out. It sounds a little more simple than getting shade cloth and making a frame.

One trick I use for the problem when possible is rotating the bulb through an emersed fixture of the same type for the first couple weeks when possible. Since there's no CO2 limitation, I just get faster emersed growth. In this case though, I've got no 18'' T8 tray :P