too much light?

softiegirl · Oct 10, 2009

Is there such a thing as too much? I recently picked up a 29 biocube to keep inverts,etc. I hated the stock light colors so i got a 20" 250 watt metal halide. I know now that it was overkill, just thought id like to possibly put some sps in there. But now im having a terrible algae problem. At first i thought it was just a cycle. Went thru the usual cyano, nitrate spike, etc. But now im getting green algae pretty badly. Using r/o water... my params are ok, nitrates are just under 20 still. could it be the light causing it? when i just leave the actinics on, i dont get the algae at all. im puzzled!!?? :squigglemouth:

zona322 · Oct 10, 2009

how long do you leave the light on? what is you mag at? how much flow do you have in the tank? i had a 250 over my 20 gal seahorse tank it did the same thing i had the lights on for 8 hours a day. i then went and looked at my mag and it was a 900 lol it is know at 1350 and no more green algae. flow is a nether big part. hope this helps some one might be able to help a little more
craig

softiegirl · Oct 10, 2009

havent measured that actually. I do have a seahorse in there so the flow is pretty low. i really only try to turn that light on for 6 hrs because of the aftermath. going to have to pick up a test.

zona322 · Oct 10, 2009

what filter is on it the stock on or i should say witch pump are you running?

softiegirl · Oct 10, 2009

maxi-jet

Reeferdood · Oct 10, 2009

Yes it is very possible to have too much light. I would say that a 250 is slight overkill for a cube, unless you plan on all acros. Also, what type of bulb is in the MH?? The reason I ask is because I have noticed on a lot of tanks that I have serviced, if they are running Current bulbs, they have issues with algae... Also, keep in mind a chiller.. IMHO

lkjr409 · Oct 10, 2009

Seems like a lot of light for a small tank... have you checked for phosphates too? Also nitrates below 20 is still kinda of high (IMHO)...try shooting for the magical "0". Second, try cutting back the lights by 1/2 hr a day until you get to maybe 7.5 to 8 h total?or so...Also maybe try a baby yellow tang (I know they are not recommended for small tanks but when it gets larger you can always sell it or swap him out). My LFS had some really nice yellow tangs the other day that were about 1.5 inches...cute...good luck

softiegirl · Oct 10, 2009

well the bulb is a phoenix 14k. nitrates are a tad high but its still cycling a bit. the lights are only running about 6 hrs a day. Decided to try the nova extreme t5 fixture, should be here next week. if thats not it, then im tearing the darned thing down! wish i would have just gotten a bigger tank to begin with!

Reeferdood · Oct 11, 2009

Bigger tanks are are good, but don't give up on your tank!! You should be happier with the T5's, over the Halide on your setup....

lkjr409 · Oct 11, 2009

Yes, don't give up!
I started a 20 gal long frag tank a few months ago...this is what I did: 1 bag Caribe Sea live sand + only 10-15 lb live rock. I never had a spike in anything and had sofites (zoas, etc) in w/in a week...they are growing like crazy, no algae. 2- 2 X 24 watt nova extremes (stock 10K and acitinics)($65/ea!)....they are on a 10 h cycle. No skimmer! Old Skilter 400 without the skimmer on for filtration, chaeto (about the size of a softball) in both back chambers on reverse daylight with a $12 - 10 inch flourescent fixture from Lowes..already had to pull out some chaeto twice because of over growth in the last 4 months...when the back light goes on you can see all the critters scurrying around in the chaeto. I have made a 15% water change only 4 times in 4 months...pH is stable, nitrates and everything else = 0. Only two fish (keeps the nutrient load down) - 6 line wrasse and tiny yellow goby. By the way, use nothing but RO/DI water!!! Hope this helps a little...

blinddog · Oct 15, 2009

Dont giv up when you make changes the tank makes changes

BlazinNano · Oct 15, 2009

I had the problem when I went from t5s on my 28 gallon to a 150W MH. the biggest thing you should try is what IKJR said, start by running the light for like an hour for a 3 days then every three day add another hour to it. Also watch that temp. I only have 150W over a 28 gallon and I have to run a little 2 inch computer fan when the lights are on or the tank gets up to 82 but I also live in Florida and it is October and still 90+ outside. I would even do the light trick with the t5s. A friend of mine had the stock BioCube hood with 2 PC bulbs in it. He went and got the upgraded one with 4 PC bulbs in it and did not adjust his tank to it. Within a week it looked like a planted tank..