ulns

[bullock]

hi all, alough im not completley new to the hobby i am to the ulns system, right ive been using the ulns in my 5x2x2 tank for about 6 mths now to start with everything was fine. now ive started to get this brown like alge on the sand bed and now moving onto my live rock and some corals, ie 2 brain corals lost and a maze also 2 dead crabs and 1 boxing shrimp for no apparent reason.in my tank im useing ultra bio every 3rd day,mins and baks daily which i have halved but still getting the brown stuff. im using a ocean runner 3500 return pump,2 power heads 1 turbelle stream 6060 and1 6040,a grotech protein skimmer,2 150watt metal halides on daily for 6.5 hours so not to much lighting.thought maybe this is diatom so why after halfing everything am i still getting this stuff, all checks nitrate ,ph, amonia checks done weekly and are all fine temp 28 degrees, salinity 1.026. the only high reading i got was phosthate which has been sorted with a rowaphos bab scrunched daily. please any help would be appreciated, oh i have about 35 corals mixed sps and softies only a handfull softies also fish are 1 regal,1goldrim,1kola,and1 yellow tang, 1 moorish idol,1 dwarf lionfish,2 common clowns,2 chromis,2 damsals,1cleaner wrasse, 1 scooter blenny, fed 2 times a day on brine shrimp and marine mix also sea veg 3 times weekley

[shaginwagon13]

...what is ulns?

[Avi]

bullock..the "brown like algae" that you're getting on the sand bed but is spreading is almost assuredly Diatoms. They aren't actually algae but instead, like algae need light but also need silicates to thive, unlike algae. At any rate, this is something very common in newly set-up marine aquariums and for the most part, other than looking nasty, isn't a threat to your tank.

The silicates come into a newly set-up tank in a number of ways...most often either with the water that's used for water changes and also with the sand that's used for your substrate.

If you aren't using RO/DI water, try to start using that because it will be reliably free of silicates. As for the sand, eventually, it releases less and less into your tank's water so that will contribute to an abatement of the Diatom issue.

There are a few other things you can do to relieve the problem. One is to turn off the lights over the tank for three consecutive days. This will not harm your coral and will clear up the Diatoms. It will, however, start up again unless you address the water conditions in the tank.

I'd recommend increasing the amount of flow that you have in the tank. I'd also recommend increasing the number and frequency of water changes you do, using a good water source. And, you can get a "phosphate reactor" and use it with a good quality phosphate removing medium like Rowaphos. These mediums also remove silicates from the water so they can be effective in reducing the Diatom problem. The reactors aren't very costly and they are driven by a very small water pump that pushes about 80 to 100 gallons per hour.

Otherwise, the Diatoms will more than likely stop being as much of a problem over time, but it would take months for that to happen.

[bullock]

hi shaggin waggon13 ulns is ultra low nutrient system

[bullock]

hi avi have added another turbelle 6040 today also another 10 percent water change, took your advice on reactor and have also ordered one of those just have to wait and see thanks for advise