I'm stumped

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Aquarium Advice FINatic
Nov 26, 2009
About 2 months ago, I went through the diatoms and then some pink algae showed up. I killed the lights for a month,all but 2 hrs every other day to feed. Now, started turning the lights on about 8hrs a day and the diatoms showed back up, then they died off and the pink algae showed up. I dug some out of the sand and the sand it was in was clumped together. I'm assuming it is cyano. Which puzzles me because I have a 75g sump with a skimmer, 50lbs of rock. the sump overflows into 2 30x18x10 wet/dry filters I am using for fuges(have them filled with chaeto.)

The params are 0 amm, 0 nitrite, 10 nitrate, 0 phosphate, 9dkh, 450calc.

I use only ro/di water and IO salt mix. I test the top off and pwc water everytime and they show zero's across the board.

The tank is 180g and I have been doing 40g water changes every week for the past month.

I don't get what is going on, I thought I had adequate filtration and the 3 hydor 750gph powerheads plus the 1500 gph water pump in the last fuge would make for great water circulation.

What else could cause this. Btw the lighting is t5ho 6x54w bulbs less than 2 months old.
So how old is your tank? What do you have in it? How and what do you feed?
4 mos old, ocean nutrtion pellets and omega 1 flakes and dried seaweed

2 clowns, powder brown tang, blue regal tang, 1 firefish, 1 mccoskers wrasse, 2 cleaner shrimp, 2 tiger cowries, 1 turbo snail, 1 hermit crab, 30 trochus, 30 nas, 20 ceriths and nerites.

I feed every other day and give what is gone in 5 mins. I put 2 pieces of seaweed in every 3 days and they are gone by nightfall
Don't worry about the diatoms they will be gone soon enough.Your tank is still very young. I would just keep up on the water changes and since you don't seem to have any corals, the reduced lighting is okay. Is the algae on the sand soft and has lots of bubbles in it?
No bubbles, it looks like pink dust on the sand's surface. If you dig up the sand, it is down in the sand and the sand clumps together. Imagine a hydrogen sulfide pocket. The black decayed waste that doesn't get stirred up and removed by sand sifter's. I've seen pics of it on here but can't remember what you guys called it. I remember someone saying to remove only one pocket every few days or it will kill the tank. That's what this pink dust lookin stuff would remind you of
Sounds like diatoms to me. Just do regular PWC's and it should clear itself out. Those black spots are hydrogen sulfide pockets and are best left alone.
sounds like diatoms still as well unless it has slime?What skimmer are you using and is it actually working,is it big enough for your 180g dt+75g sump+ 2xwet/dry tanks which is close to 300g??
you stated that your lights where two months old and were t5ho 6x54w bulbs, What did you have before that and how deep is your tank.
the whole setup is new. I built the lights myself. I have a reef octopus extreme 12 inch skimmer. tank is 24 inches deep, 3 in deep sandbed. Is there such a thing as pink diatoms?
If it's the octopus extreme 200 then it's made for tanks up to 225g your tank volume is a lot larger than it can cope with,you may need to rethink the skimmer.
I ordered it from reef specialty and thats what the box said was extreme 12 inch up to 400g capacity. Judging the size of it, at first glance I would think it would be for a pond. It is huge. Any guess on the whole pink diatom theory.
Just another aspect I see is that`s a pretty big bioload for just 4 months. That where alot of your excessive nutrients are coming from. Not enough nitrifying bacteria for that size load.
I went through a small diatom bloom when I changed my lighting system From T-5 HO to T-5 VHO and it went away by itself. Don't panic and just take one step at a time. I would really slow down your feeding. And yes, pink is just a lighter shade of brown and is more then likely caused by the K values of your lights.
all the fish and everything came from my 75g. While the tank was cycling the ammonia shot up to 4ppm(extreme die-off apparently) after ammonia and nitrite hit zero and I showed around 20 nitrate. I changed 100g of water and in the fish and inverts went. I kept the 75 running for around 2 weeks in case anything went haywire. I tested twice a day and never saw ammonia or nitrite, and my nitrate has never went above 10 since I added the 2 fuges and the sump. Before, the nitrates hung around 20. I wish I still had my camera to show you guys pictures of it.
I started turning the lights back on 8hrs a day yesterday and here come the brown diatoms again, although this time they don't look to be anywhere as significant as the previous arrivals. I already see the pink sections(dusty looking and feeling) in the sand. Thistime, I'm gonna let it ride and see what happens. Still getting the usual zero's on the pwc and top off water and on the tank itself plus 10 or less on nitrates. Man the first few months to a year are a pain. My cichlid tank is nowhere near the headache as this tank is. I haven't had any catastrophies yet but going through the ugly begginnings bites.
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