Silicates / Diatoms Question

[Jeremy Luke]

I started up my new tank a couple of months ago. A few weeks ago I had a small diatom bloom. I ran some GFO for 36 hours that knocked it out.

Last night I a diatom bloom started to appear again on the rocks and glass. How long would it take after introducing silicate for a bloom to appear? The source possibilities at this point is a short list.

1) the trash can I'm mixing my water in. (I performed a 10% change on Tuesday night)
2) Wendesday night I started running my dual reactor again only on a timer to kick on for 15 minutes 3 times a day. The GFO in the the reactor was used twice previously. First time was for 36 hours and it knocked the phos from .08 to .01 (Hana ULR) and the 2nd time was for 20 hours and it knocked the phos from .09 to .02. It's 3/4 cup of GFO. I believe my actual net water volume to be about 100 gallons.

The bloom I noticed Thursday evening when I returned home from work at 5pm. My light schedule is

4 54w T5 Blue+ 2pm-10pm
2 250w Radium Halides 3pm-9pm

What do you think the culpit here is? Thanks folks.

 

[Jeremy Luke]

Additionally, my phosphate on Wednesday before running GFO again was .055. Thursday night the phosphate was measured to be .06 so given the little bit of time that the reactor ran it would appear that it was somewhat maintaining the phos rather than leaching. I feed pretty heavy and the tank is now well stocked with fish.

 

[saltyfilmfolks]

Was it dry rock?
Its the rocks most likely. Thats why diatom blooms are a common occurrence in the ugly phase when a tank is started with it.

 

[Jeremy Luke]

Thanks saltyfilmfolks, i was indeed dry rock. Marco Rocks. I upped the reactor time, hopefully it will knock it down again. I just want to make certain I don't drop my phosphates too low. I've started to add SPS and I don't want them to lose their color.

 

[saltyfilmfolks]

Thanks saltyfilmfolks, i was indeed dry rock. Marco Rocks. I upped the reactor time, hopefully it will knock it down again. I just want to make certain I don't drop my phosphates too low. I've started to add SPS and I don't want them to lose their color.

go slow. they'll pass on their own too.

 

[Jeremy Luke]

Thanks. I'm now running the reactor for phosphate management, not focused on the silicates. That's why I'm now trying it on a timer instead.. to maintain them low but not zero.

 

[saltyfilmfolks]

Thanks. I'm now running the reactor for phosphate management, not focused on the silicates. That's why I'm now trying it on a timer instead.. to maintain them low but not zero.

gotcha. good plan. The only concern on a reactor on a timer is the water does become stagnant in it. Id consider just lowering the dose amount.

 

[BlueCursor]

I would not worry about silicates if you are following the basics: RO, RI for mixing salt water and you didn't use sand as a substrate.

My tank is over 4 years old. If I add too much carbon dosing I get lots of diatoms. If I run too many biopellets I get lots of diatoms. I have tested my silicates a few times and they are always 0! The only time my diatoms were non-existent was when my tank was completely depleted in carbon. But then my corals were not growing.

 

[Jeremy Luke]

Thanks for the tip on the stagnant water. I'll try to reduce the amount of GFO even further. I'd love to just run it constantly and keep the Phosphates above .03 but below .1. Thus far my nitrates are staying in the 5-10 range (with regular water changes) so hopefully I won't need to worry about carbon dosing or other means of nitrate export. The tank has a good amount of fish in it and I feed fairly heavily.

 

[saltyfilmfolks]

The tank has a good amount of fish in it and I feed fairly heavily.

yup, no sweat. I would try to focus on feed ing healthfully. as the tank and biofilter mature itll take care of itself, and you don't actually need reactors etc. Once my tanks reached an age I was kinda surprised I had to feed a bot more, just for the tank, as it ate up nutrints pretty fast.