Replacing the Sand Bed

[SaltyMix]

Hi all and thank you in advance,

My LFS guy and I have been dealing with a major phosphate spike in my tank that led to a hair algae bloom and a ton of problems. The problem is there was really nothing to cause it that we could find…until today.

Despite consistent water changes and purigen and everything else, my phosphates have been consistently 2.00ppm and between 0.00-1ppm in nitrates for about 2 months now.

Calcium is at 380
DKH is at 11
Salinity is at 2.5

My tank is a 30 gallon. Running a canister filter with purigen and carbon.

I additionally have almost too much clean up crew (30 snails, 12 blue legged hermits, 2 conch, 2 peppermint shrimp, 1 brittle star, 1 Luzon starfish, and 1 white pincushion sea urchin, 1 porcelain crab). I’m feeding 1/5 cube of frozen food 2 times daily and a small nori strip about 1 per week (switched from frozen marine cuisine suspecting that the krill was not being eaten by the tank to plain mysis shrimp). Nothing is dead (I checking for life in all livestock at least once a week), and clean the sand bed every water change. I have no macro algae. I do have some corals and want to add more.


My fish are as follows: 2 oscillaris clowns, 1 banggai cardinal, 1 fire fish, 1 mandarin dragonet, and 1 baby tomini tang (the tang is for algae control and will go back to the LFS once she’s grown a bit on agreement/recommendation with the shop), and one Indonesian anemone. All my fish have a good condition score, with none being too skinny or too fat and they’re all voracious eaters.

Today, with my water test my LFS guy finally asked me what my sand bed was and if it was argonite.

Surprise! It’s not! He said that’s definitely the problem and explains why I could never get my sea cucumber to go on the sand bed and finally just retuned it to the store because I knew it wasn’t going to make it in my tank.

From my pictures we couldn’t tell exactly what the sand is and I don’t remember the brand. I just know it was one of my first tank buys at a smaller fish shop. (Pic attached).

I had no idea that argonite is important. So he recommends I replace the sand bed since it’s probably leeching pollutants into the water and do a 50% water change. (All my corals and fish are healthy so whatever is leeching in isn’t doing damage yet).

The problem is the web warns that using caribsea live reef sand (argonite), which is what I took home to do this with, will upset the bacteria in my tank. I’m not sure that’s even a problem at this point since I’m having so many issues with phosphates and hair algae.

Can I replace the sand bed all at once with the live reef sand? I don’t want to risk the sand mixing and just have this problem continue.

Any thoughts on how to do this safely?

My LFS guy just said “switch the sand bed” and it’s utterly my fault for not getting a recommendation/instructions on exactly how to replace it and of course the LFS is closed for the weekend so he can go on vacation. I live in a rural area and my LFS is about 1 hours drive away.

I’m just so relieved that after everything this might be the answer.

Also, newbie reefers, don’t let your local mom and pop store that doesn’t have marine fish sell you any old aquarium sand…which is what happened to me. Apparently it’s got to be argonite.

 

[Subsea]

Substrate does not have to be aroggonite. I like using aroggonite because of its buffering properties.

Not quite sure that I understand the problem.

I don’t understand your parameters of salinity. Please explain.

Calcium is at 380
DKH is at 11
Salinity is at 2.5

 

[fish_collector]

I doubt your issues are related to the sand in your tank, but maybe I guess. Yes aragonite or crushed coral is typically what's used for marine tanks. I've always been told it was due the alk and pH buffering ability of it, but in my opinion we keep our marine tanks near 8 but aragonite should be inert at that pH. To realize any kind of buffer the pH would have to be down in the 6s, like in a calcium reactor, but that is well out of the scope of what the OP is looking for .

You will get a variety of responses regarding removing the sand bed of a marine tank all at once with the primary reason being the unwanted release of hydrogen sulfide trapped deep within the sand bed. I personally don't believe that to be the case because sand beds aren't usually deep enough or made up of fine enough grains to go anaerobic, which is what's required to form hydrogen sulfide gas. If your sand bed was 6" deep and made up of sugar sized grains then yes there could be issues. But let's say if it was 2" deep and made up of grains that were 1-2mm then you'll be fine to use a siphon hose to remove it. It siphons out rather quickly. I've removed several sand beds from my aquaria all at once and never once saw any bubbles that had formed from within and never had any bad reactions to doing so. But as I said you'll get some others who will say don't try it lol. I've done it and it was no big deal.

The Caribsea sand, Aragalive I think is what it's called, will be dirty if you put it into the tank without rinsing it a bunch of times in a bucket, but the caveat to that is you are going to kill off whatever kind of bacteria is in the sand by doing so, so you'll have to use salt water to rinse it. It has been debated that what is in the Caribsea Aragalive isn't super effective for nitrification anyways but it's still a good product to use, I used it my reef tank originally as well. It does need to be rinsed before use or else it'll cloud the tank water for several days, mine did.

Perhaps you can check to verify your source water is clean and as near 0 TDS as you can get it. Often times you can create odd problems by using source water that's not pure enough. High nutrient levels and nuisance algae in a tank that's less than 6 months old is common. There's almost too many things that could cause the issues you are having to list them all here. Swap out your sand if you want to, and just be patient with it. I've found it easier to make one change at a time and then leave the tank alone for a while to see if your change has the effect you were after.

This probably wasn't as helpful as you'd have liked, sorry.

 

[fish_collector]

Maybe the OPs salinity is 1.025?