Two tanks, same water, totally different ALK

[JoJosReef]

Riddle me this...

A 10g office tank and a 13.5g home tank use the same water (HG, mixing around 7.7dKh @ 1.026sg). The former almost never runs ALK > 8, despite daily 3mL All-For-Reef, the latter 9.9 currently with no additives.

What could be the reason for the disparity?

Tank details below.

Office 10g:
100% rocks and sand from Tampa Bay Saltwater, lots of hitchhiking corals, tunicates, sponges, etc., residents include tailspot blenny, exquisite firefish, crocea clam, fast-growing codium, fastish-growing brotycladia, one torch, one octospawn, one splitting head hammer, one mint pavona, one acro, little piece of pom pom gracilaria, zoa/paly/clove island, 4x RFAs, 2x sexy shrimp, 2x porcelain crabs, 1x pom pom crab, an emerald crab, a favia, a gorgonian and a bunch of varietal snails; tank usually runs ~2ppm NO3, and varying PO4 (was down to near zero then up again to 0.1ish). Tank has been running for 8 months. Tank has a very small patch of manageable GHA and a semi-serious bubble algae problem.

Home 13.5g:
50% rocks from Tampa Bay Saltwater (a few remaining hitchhiking tunicates/cup coral and small bivalves), 50% CaribSea LifeRock, 25% TBS sand + 75% CaribSea fiji pink livesand; inhabitants include 2x ocellaris clowns, serpent starfish, Saron shrimp, pom pom crab, 2x small conch, 1x pitho crab, varietal snails, 1x randall's pistol shrimp, large pulsing xenia island, alveopora mini-island, trumpet coral, a few zoas, 1x large RFA, 2x acans, 1x blasto merl, 1x blasto wells, large GSP island, 1x scoly, 3 types of mushrooms, 1 stalk of brotycladia, 1 small piece of codium taking root; tank usually runs 10-25ppm NO3, 0.5-1ish ppm PO4. Tank has been running for 11 months and has battled diatoms, ostreopsis dinos, and multiple rounds of plague level GHA.

Any thoughts? Thanks!

 

[Fish Think Pink]

Riddle me this...

A 10g office tank and a 13.5g home tank use the same water (HG, mixing around 7.7dKh @ 1.026sg). The former almost never runs ALK > 8, despite daily 3mL All-For-Reef, the latter 9.9 currently with no additives.

What could be the reason for the disparity?

Tank details below.

Office 10g:
100% rocks and sand from Tampa Bay Saltwater, lots of hitchhiking corals, tunicates, sponges, etc., residents include tailspot blenny, exquisite firefish, crocea clam, fast-growing codium, fastish-growing brotycladia, one torch, one octospawn, one splitting head hammer, one mint pavona, one acro, little piece of pom pom gracilaria, zoa/paly/clove island, 4x RFAs, 2x sexy shrimp, 2x porcelain crabs, 1x pom pom crab, an emerald crab, a favia, a gorgonian and a bunch of varietal snails; tank usually runs ~2ppm NO3, and varying PO4 (was down to near zero then up again to 0.1ish). Tank has been running for 8 months. Tank has a very small patch of manageable GHA and a semi-serious bubble algae problem.

Home 13.5g:
50% rocks from Tampa Bay Saltwater (a few remaining hitchhiking tunicates/cup coral and small bivalves), 50% CaribSea LifeRock, 25% TBS sand + 75% CaribSea fiji pink livesand; inhabitants include 2x ocellaris clowns, serpent starfish, Saron shrimp, pom pom crab, 2x small conch, 1x pitho crab, varietal snails, 1x randall's pistol shrimp, large pulsing xenia island, alveopora mini-island, trumpet coral, a few zoas, 1x large RFA, 2x acans, 1x blasto merl, 1x blasto wells, large GSP island, 1x scoly, 3 types of mushrooms, 1 stalk of brotycladia, 1 small piece of codium taking root; tank usually runs 10-25ppm NO3, 0.5-1ish ppm PO4. Tank has been running for 11 months and has battled diatoms, ostreopsis dinos, and multiple rounds of plague level GHA.

Any thoughts? Thanks!

Different corals uptake differently and at different speeds - its why its always recommended to test water parameters. Good for you for testing. Now you can replace what each tank needs., as each tank needs it dpending how each tank is growing. Likely you notice more growth happening in the tank where you need to dose (its also why you need to dose). I'd suspect lighting and/or feeding differences are also contributing factors, but as they grow then they take it from the water.

You have gotten A LOT into each of those small tanks - WOW

 

[JoJosReef]

Different corals uptake differently and at different speeds - its why its always recommended to test water parameters. Good for you for testing. Now you can replace what each tank needs., as each tank needs it dpending how each tank is growing. Likely you notice more growth happening in the tank where you need to dose (its also why you need to dose). I'd suspect lighting and/or feeding differences are also contributing factors, but as they grow then they take it from the water.

You have gotten A LOT into each of those small tanks - WOW

Thanks! Attached pics of the 10g which is my pride and joy, just because.

What is most curious to me is that ALK goes up in the 13.5g home tank. Lighting and growth are huge differences--the 10g is growing very fast under an AI prime (AB+ Saxby mod), while the home tank is growing much more slowly under 21LEDusa Reefpro Deep Blue bars on a fixed 8-6pm + ramp up/down schedule.

I'm sure there's so much going on in these tanks affecting water chem, but it's definitely perplexing.

Thanks!!

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