Does my water chemistry need adjusting?

[Augy]

I have 5-6" DSB made up of Southdown and around 125 lbs of Live Rock in a 90 gal display with a 29 gal sump. The tank is about 4 months old now and all hermits. corals, and fish seem to be doing well. Some snails are not doing as well but that could be predatory rather than water chemistry.

I have lost 2 peppermint shrimp and a cleaner shrimp as well as 2 emerald crabs over the past 2 months or so. I've never had a lot of luck with emeralds but they usually survived a year or better. I've never had trouble keeping shrimp so this is new to me. Now I'm finding what feels like a few too many empty snail shells.


Water parameters...
PH 8.2
DKH 11
Calcium ~350
Ammonia 0
Nitrites 0
Nitrates 0 (or very close to it)
Phosphates 0
Temp 79 - 81
Tropic Marin Salt

Bio-load....
1 Yellow Tang
1 Royal Gramma
30 or so hermits
20 or so snails
1 Fox Coral
4-5 Mushroom Corals
1 Xenia (medium)

300 W MH + 200 W PC (actinic) + 3 LED moonlights
Berlin Classic Skimmer

The coraline algae hasn't started growing as much as I would have expected at this point. Could that be a factor of the calcium level? I don't want to start adding a bunch of chemicals to the tank but the lack of success with the shrimps and emeralds has me concerned as well as (to a lesser degree) losing a couple of conch's and a dozen or so other snails.

Any suggestions? Thanks.

 

[afishyonados]

Calcium should be a tad bit higher, but the lack of coralline may be lighting. New halides often retard or discourage the growth of calcerous algaes.

Salinity swings could be the cause of the bodies...

But, more likely is the presence of a larger predator. You may have a mantis shrimp. Are the empty shells in the same area?

Can you look up under the stand and see the bottom of the tank? If so, look for grey or black patches in the sand bed. The quantity of sand in the tank may be too much. If the grain size is uniform (which it is) the anarobic by-products can amass and build into a toxic time-buh (I don't like saying the word, much less typing it).

 

[Augy]

Yes, the shells are pretty much confined to one area.

Regarding the DSB, I will look under the tank tonight and see what it looks like and post back.

 

[afishyonados]

When the shells are confined to one area, it definately screams of predator! Investigate methods of trapping mantis shrimp.

 

[Craig Lambert]

I would check magnesium as well. Then raise magnesium to 1300-1350. Once that has been done, use calcium chloride to raise your calcium level to 425-440. (Kent's turbo calcium or similar). Then return to Kalk, or a two part solution to maintain calcium and Alk.

 

[Augy]

<a href=showthread.php?s=&postid=7198604#post7198604 target=_blank>Originally posted</a> by afishyonados
When the shells are confined to one area, it definately screams of predator! Investigate methods of trapping mantis shrimp.

Sounds like fun (ugh). Don't you typical hear a mantis shrimp "clicking"? I've never heard anything. What are other signs of a mantis (aside from homicidal evidence )

Thanks for the help...

 

[Augy]

<a href=showthread.php?s=&postid=7198624#post7198624 target=_blank>Originally posted</a> by Craig Lambert
I would check magnesium as well. Then raise magnesium to 1300-1350. Once that has been done, use calcium chloride to raise your calcium level to 425-440. (Kent's turbo calcium or similar). Then return to Kalk, or a two part solution to maintain calcium and Alk.

Thanks. I'll have to get a test kit and then do some research to better understand how all those affect one another.

 

[Craig Lambert]

Magnesium
http://www.advancedaquarist.com/issues/oct2003/chem.htm

Reef Aquarium Water Parameters:
http://reefkeeping.com/issues/2004-05/rhf/index.htm

What is Alkalinity?
http://advancedaquarist.com/issues/...2/chemistry.htm

Calcium:
http://advancedaquarist.com/issues/mar2002/chem.htm

Magnesium in Reef Aquaria:
http://www.advancedaquarist.com/issues/oct2003/chem.htm

The Relationship Between Alkalinity and pH:
http://www.advancedaquarist.com/issues/may2002/chem.htm

Solving Calcium and Alkalinity Problems:
http://www.advancedaquarist.com/issues/nov2002/chem.htm

 

[Augy]

Wow, wish I would have studied chemistry in college

 

[Sk8r]

Augy, pick out a few of your specimens that don't look quite happy, then test the water. When you correct whatever was the problem, note how they look now. I have alkalinity bellwethers (my fish), calcium (my frogspawn), and needs-a-water-change (my lps.) Sometimes a glance is faster than a test kit. Mg I haven't found one for, but the coralline growth slows if it's low.