Siphon this?

[djp183]

Going on 2 months with diatoms. Weekly R/O water changes, skimmer, carbon/GFO, polyfilter/floss, increased flow (Nero 5), dosing alk/ca, reduced lighting (~8 hours on). I’ve been siphoning the top layer with each water change but should I let it just build up instead? Should I stir it? When I siphon I lose a small amount of sand each time. Nem, corals, fish all doing fine. I should add that I have an adult hitchhiker mantis shrimp and 2 juveniles that leave the fish alone but snails and hermits don’t last very long. Tried catching them with bottle traps, etc but they’re too savvy and I’m not about to tear everything out and start over. even if this becomes a stomatopod-specific tank. Thanks in advance for any tips!

[jservedio]

Are you just using RO water or RODI water? If it's just RO, it could be silicates in your water feeding diatoms. If that's the case, you can either siphon them or just leave them be and add a DI stage to your RO machine.

 

If you are already using RODI, I would be really concerned it's not actually diatoms... If you are using RODI, can you take a closer picture with white lights on? If it is in fact diatoms, you can probably switch out your DI media to cartridge with special silica resin added in - Spectrapure calls theirs the "Silicabuster" cartridge.

 

That said, you have a TON of filtration for a new tank that doesn't look particularly heavily stocked - my biggest worry would be that you are going to be bottoming out your nutrients, particularly phosphate, and end up with dinos or chysophytes. Why are you running all of that on a new tank? What are your Nitrates and Phosphates at?

[djp183]

Thanks; I have 2 chromis, 2 clowns, and a 6 line wrasse so the bioload is moderate I think on the 40 gallon. I think it’s just RO (attached a pic). I would need a tds meter to check the silicates, right? Here’s a better shot with just whites:

[jservedio]

Well, that definitely looks like diatoms - I was worried with how long it was going on that it was dinos since early on they can look pretty similar. You only have an RO system - no DI. If your city provides a water quality report, you can find out how much silica you have in your water to see if it'd be a problem for regular DI media, but a TDS meter isn't going to tell you what is actually in the water. For a reef, long term, you absolutely want a full RODI - especially since you clearly don't have a budget build. Having RO only will likely lead to issues down the road since RO water is going to have nutrients in it.

 

You really, really should have both Reverse Osmosis and Deionization. You can add a DI stage to your RO Buddie, though it's a pretty crappy system overall since the filters are proprietary and tiny. I would consider selling it and upgrading to a proper RODI system (like one of the BRS or Spectrapure ones), or if that's just too much - add on a full-sized DI canister (2.5x10") instead of using the RO Buddie tiny little DI stage. If the DI doesn't make it clear up right away, you can switch it up and use a Spectrapure Silicabuster cartridge, but they are a little more expensive ($30 vs. $14 for a basic DI resin refill).

 

A 4-stage BRS system is only $150 and a nice Specrapure one is only $180. You can add a DI canister stage to your RO Buddie for about $48 with an RODI canister, a DI cartridge, and a few feet of tube.

 

Edit: If you are just building your own DI stage for your RO Buddie, you would need the following items from BRS

• 10" Reverse Osmosis Canister 1/4" Ports - Bulk Reef Supply - $16.99
• 2.5" x 10” Clear Refillable Cartridge for DI Resin (Standard) - $7.99
• One Cartridge Refill (1.25 lbs.) DI Resin (Color Changing) - BRS - $13.99
• 2x Mur-lok Swivel Elbow 1/4" NPT x 1/4" Push Connect - $3.49/ea
• 5 Ft - Blue 1/4" RO Tubing - Mur-Lok - $1.99

[djp183]

Thanks; I always thought the buddie seemed tiny and not quite up to the job. I will check out those other systems you mentioned. I’m in the country and on a well so I don’t think I have a lot of chemicals going in, but we do have an acid neutralizer for hard/high ph.