Snails all dropping off rocks???? pH???

The past week i have noticed the snails (astrea & turbo) started to drop off the rocks and lay upside down in the sand. Now more and more are doing so, almost all of them . Just laying in sand upside down. There are no predatory creatures and most snails have been there for years.
I have had ph problems & been trying to correct this over past few months by adding kalkwasser by the boat load. pH only stays up while kalk is being dripped. If I don't keep kalk bottle dripping then pH immediatley begins to drop. Also adding alk buffers constantly as dKH constantly dropping.
I do have a huge ASM G4 skimmer which pulls air from outside as sump is outside. Main tank is completely sealed inside and all filtration is done outside.

Temperature: 77.8
PH: 7.88
Ammonia: 0
Nitrite: 0
Nitrate: <10
Salinity: 1.022
dKH/KH/Alkalinity: 11
Magnesium: ? testing later today
Calcium: 440
Phosphate: 0.5

Tank size? 350
Estimated total system? 450 - 500

Reef, fish only or, freshwater? reef

Current inhabitants? What and how many? too many to name. fish soft and hard corals
Clean up crew? snails , brittle stars, hermits

How long has your tank been set-up? 3 years

Substrate.
Type? fiji sand #3 grade
Depth? 2- 3"

Live rock?
How much? ~350lbs
Did you recently add some? no

Filtration.
Type? Fluidized bed/ pleated cartridge / carbon
Protein skimmer? ASM G4

 

Hello! Your pH and salinity values are low! That may explain why your snails are having a bad time! Invertebrates are very sensitive to pH oscillations. Moreover, pH is directly related to the biologically accessible oxygen content! Adjust your values, slowly! Use some quality product for pH adjustment -> Seachem Reef Buffer! Try not to use Kalkwaser! It will obviously rise your pH, but still decrease the buffering capacity of your water! Consequently you will end up with large pH variations! Good luck!

 

I've been using Reef Buffer regularly. pH rises for a day or so then drops again.
Is this because of the kalk?
So stop using kalk and keep using Reef Buffer.

 

Your pH should be around 8.2 or 8.3. Not sure about the Kalk, but I use buffer periodically and my pH is perfect. Specific Gravity should be closer to 1.024 or 1.025. Camilsky gave some good advice.

 

I know where it should be, i'm having trouble getting it there though.
Still doesn't explain the snails either.

 

That's a huge tank (and 3 years old at that!) to be having those problems. The salinity is very low, the pH is very low, and the temperature is at minimum. But, the good news is that the Amonia/nitrite/nitrate is excellent, so you don't have any dead creature hiding in the back and fouling your water. Do a 10%-15% water change with high-salt replacement water (like 1.035 or higher) to bring your salinity up.

 

The PH should not be dropping that fast after Kalk stops. Temp and salinity look normal to me. It could be dropping fast because of a heavy fish load .=..CO2. Another thought..
is this the PH in the morning or evening...check both... Do you have a lighted refugium to balance the PH swing?

You may try more surface agitation to release more CO2.

Another thing I check into... have the store test your PH. and are you using the color test cards or an electronic tester?

 

How are your other inverts doing? Is there a possibility of an unknown copper source? And if your Mg is off, maintaining anything will be a challange. So I would test for copper and sort out your Mg. Your SG is low but not so low that snails would be dropping like flys IMO. You can raise that by no more than .001 per 24h.

And you have one mammoth tank dude. I am in awe.

Rock on.......John.

 

My 0.02$:

1. Check your alkalinity ! If its high -> way above 12 dKH you need to bring it to smaller value using dKH(-) product! However, if the values are below 8 dKH you should first adjust pH (proceed to step 2) and then adjust dKH!

2. Check pH! If your pH is lower than 8.3 start dosing Reef Buffer (do not exceed 0.1pH unit/day)!

3. Once you have reached desired pH (always wait for at least 6h before you check the pH after buffer addition). Proceed with dKH check and adjustment! Every dose of ReefBuffer increases dKH in small increments! So dKH adjustment should not be difficult!

Note: Please remember that pH and alkalinity are coupled. The latter one characterizes the buffering strength of your marine water. The higher dKH the more of strong acid or base you need to add in order to make big pH change! If your measured dKH is high, that may explain why there are no siggnifican pH changes upon addition of ReefBuffer!If you don't find my explanation satisfactory enough please refer to the following link:Alkalinity and Water Quality and read about the pH/alk. relation! Good luck!

 

Baked baking soda worked great for my pH problem...