Definitely need advise

[pgsasi]

HI,
I have been very unsuccessful with having corals in my tank though the fishes are all fine. One variety of star polyps and discus corals are fine. Everything else dies. On an average, corals die after about 5-6 weeks after I introduce them...

I provided my water for testing at a local shop and the results are below.

Temperature - 26
Specific Gravity - 1.026
pH - 7.8
Ammonia - 0
No2 - 0.6
No3 - 57
Calcium 413
Alkaline - 5.6

The sample collected was just before I had my scheduled monthly water change. I change my 80L of water once a month and my tank capacity is about 150L. I have loads of live sand and live rock in my aquarium and a Eheim professional filter. I also have a small filter with carbon. What should I do to ensure I can have corals ??

Please help.
Regards / Sashi

[ricksreef]

what standard are you/they using for alkalinity? m/eq? dkh? if it's m/eq, your too high, if it's dkh, your to low. I'm thinking it's dkh with the low pH to match.
but I'd concentrate on also getting your nitrates down to below 10-15 ppm (preferably below 5) before you attempt more corals.

[pgsasi]

its dkh... how do I increase this ?? and how to bring down my nitrates ? I do not have a lot of fish in my aquarium...i feed them both pellets and frozen brine shrimps.
What else shld I improve ?

[reefplayground]

Also, what kind of lights are on your system?

Do you have a protein skimmer on the unit?

Do you know your phosphate levels?

Do you use RO/DI water or Tap?

[reefplayground]

My post got messed up.

You need to lower those Nitrites to zero

Lower the Nitrates to bellow 5 pppm, closer to 0-1.

Raise the dKH, there are a bunch of products on the market which will raise your dKH or PH/dKH.

Your ph also needs a little bit of a boost to 8.2.

You nitrates can be brought down with water changes (more frequently than once/month, up it to once/week.

There are also chemical resins which will help remove the nitrites and nitrates from your system. ie: Purigen, polyfilters

[gregr]

To add to the great advice you already got- try to figure out why the nitrates are high. It could be a combination of things like dirty water (ro/di?), over feeding, under skimming (skimmer?) and the cannister filter being dirty. Cannister filters aren't used on reef tanks much anymore because they are a pain to keep clean and there are better/easier ways to maintain good water quality. Theoretically a good skimmer, a deep sandbed and lots of liverock are all you need. I say theoretically because a lot depends on how many fish you have and how much you feed. Speaking of feeding- I'd suggest adding some mysis shrimp to your fishes diet. I highly recommend rinsing your frozen foods before adding to the tank- it makes a difference.
There are different ways to keep your alkalinity and pH (and calcium) levels balanced. Two part solutions like B-ionic, adding kalkwasser to your top-off water, or a calcium reactor are the 3 main ways I'm familiar with. The two part solution is the easiest if you don't have very many corals.

[metalhead]

To add to the great advice you already got- try to figure out why the nitrates are high. It could be a combination of things like dirty water (ro/di?), over feeding, under skimming (skimmer?) and the cannister filter being dirty. Cannister filters aren't used on reef tanks much anymore because they are a pain to keep clean and there are better/easier ways to maintain good water quality. Theoretically a good skimmer, a deep sandbed and lots of liverock are all you need. I say theoretically because a lot depends on how many fish you have and how much you feed. Speaking of feeding- I'd suggest adding some mysis shrimp to your fishes diet. I highly recommend rinsing your frozen foods before adding to the tank- it makes a difference.
There are different ways to keep your alkalinity and pH (and calcium) levels balanced. Two part solutions like B-ionic, adding kalkwasser to your top-off water, or a calcium reactor are the 3 main ways I'm familiar with. The two part solution is the easiest if you don't have very many corals.

I agree with gregr... Make sure you clean that canister filter thoroughly on a weekly basis if you continue to use it to avoid nitrate accumulation in the system. Go with the two part alk/ca supplement (I like b-ionic) for now and you can look into a calcium reactor later on for a more economical solution. Other than that, if you're not running a skimmer make getting a good one your top priority.