Success with PC lighting

[saltank]

For those of us who use just pc lighting for our reef tanks, who has had continual successful coral growth and for what length of time.

My experience with 46gal + 14gal sump with skimmer, LR, shallow sandbed, chaeto in sump, excellent water flow - 206watt PC (110w 50/50 bulbs and 96W 10,000k bulb), 18w pc over sump, filter sock in sump is this:

experienced excellent coral growth of various leathers, shrooms, monti, torch, frogspawn and xenia for well over a year (tank has been setup for just over 2 years) - Within last 6 months cyano that I can't seem to beat and little to no growth in the corals

My parameters calcium 420-440, alk 3.7, nitrate not detectable, no nitrite or ammonia (haven't tested for phosphates-I know this could be a culprit, I ran phosguard about a month ago and it turned a yellowish meaning it soaked some stuff up)

Also my calcium ran low for awhile, approx 340-350 but I've brought it back up and holding steady.

I have relatively new bulbs in the fixtures - so I am wondering, is my lack of continued growth and reproduction just limited by the type of lighting?

Just trying to rule out causes, even my shrooms seem to have stopped multiplying in the last 6 months, they were going like crazy before???

Appreciate your sharing your experiences.

Oh yeah, feed flake, cyclopeeze, live hatched baby brine, plankton and mysis, and I try to be careful not to overfeed

Thanks

 

[tazdevil]

How old are the bulbs? You stated :

I have relatively new bulbs in the fixtures

But how old are they really, and are they exact same type you had before?

 

[saltank]

the 110 watt bulbs are 1 month old, the 96watt 6 months

 

[fungia]

i had a 50 gallon with pc lighting for 2 years and the corals grew very well and had great colors. i did not have a cyano problem in my tanks, i wonder if it is more a problem with water quality.

 

[Anonymous]

I had a 55 gallon tank lit with PC for about 6 years. I had soft corals, a bta, some lps corals, and even a crocea. Little white snails got the crocea but before it croaked, it doubled in size, which suggests the PC were enough. Everything else grew like weeds. I had four 55 W and two 96 W lamps.

I've started over now with a larger tank and a combo of HQI halides and PC lamps. I like it better.

 

[Anonymous]

Within last 6 months cyano that I can't seem to beat and little to no growth in the corals

This is low oxygen content, not lighting. It indicates poor water circulation and an excess of nutrients (I blame the flake food, from what you describe). Increase the water circulation, clean or upgrade your skimmer, etc.

If cyano is getting really out of hand, there is a comparatively safe nuclear option: erythromycin

It will kill off the cyano pretty quickly, often with a single dose, and the impact upon the nitrifying bacteria is fairly minimal.

 

[saltank]

Hey thanks for the replies.

You know I have thought about oxygen but I thought if anything it would have improved with my installation of a sump about 3 to 4 months ago.

Overall for circulation I have: Mag 7 return pump (although it is throttled back quite a bit, the return wasn't handling the volume at full speed), 2 ph in the display both turning about 240gal/hr and a rio attached to the skimmer in the sump turning another 240gal/hr. In total I've got to be turning over 900+gal/hour (or about 17 times volume per hour). You know what, now that I have calculated it, that may be low!

How many time volume/hour should I shoot for?

Also, is 4 1/2 watts per gallon of pc lighting sufficient? It seemed to be before.

Since posting I've realized too that I have "lost" a fish and a starfish in the tank. Never found the fish and by the time I found the star it had decomposed quite a bit (it was rather small thankfully, about 1 1/2 inch in diameter).

Thanks again, I appreciate any input on the matter :wink:

 

[Anonymous]

I would try to change at least 50% of the water, siphoning out as much detritus, dead stuff, and cyano as possible. The more you can change the water, the better.

 

[saltank]

I did a big time cleaning about a month ago. I was actually tacklin the bubble algae that got out of control, syphoning them into a filter sock.

In the process I sucked out probably in excess of 1lb of cyano, detritus and bubble algae - of course immediately removed the filter sock and put a clean one in.

It seemed to help somewhat, but I am really thinking I am adding to the problem b/c my ro/di filters need replaced, new ones are on the way.

Thanks!