Diatoms on Sand bed

[quicksil328]

Hi everyone. I am hoping someone can help me a bit here. I am having a small problem with Diatoms on my shallow sand bed. I have noticed this to be the case over the course of the last month. My total water volume is approximately 250 gallons (190 display, 35 in sump, 40 refugium). I have been changing approximately 50 gallons every 7-10 days with rodi topoff My tank is lightly stocked with about 8 fish and 2 small coral frags right now. My sump is running an asm g4 skimmer and I have a mag 12 pumping water up to a 40 breeder that I am using as a sort of refugium growing a small laundry basket full of chaeto. I am running a Two Little Fishes Phosban reactor and I have another that I could set up. My sand bed is 3-4 inches deep. I have approximately 175 lbs of rock. I am using a maxspect gyre with 2 hydor koralias for water flow. My lighting is an ATi 6x80 watt Sun Power fixture running about 8 hrs a day. When I test my water I get the following readings:
PH-8.1
SG-1.025
Ammonia-0
Nitrite-0
Nitrate-<5
Phosphtae between 0-0.25
Calcium-380
Magnesium-1500
Kh-11
Temp 79-80
The diatoms just don't seem to go away. Any help would be appreciated.

 

[ClearView Lids Verified Sponsor]

Where is the water coming from that you use for your water changes and top off? Checked your TDS and/or replaced system membranes recently? What brand salt are you using?

On a side note, you can probably back off some on those water changes. What kind of coral are you planning to keep in your system? Softies and LPS or are you going for SPS dominant?

 

[quicksil328]

I was thinking mainly softies and LPS. I have city water connected to a new BRS 75gpd unit. Well the RODI is about 6 weeks old so the membrane shouldn't be a problem. My tds reads about 004. I have been using Instant Ocean salt (purple bucket). Do you think the basket I am using for my chaeto could be leaching something in the water?

 

[quicksil328]

Anyone have any ideas

 

[Avp]

I've been having a similar problem for months now but can't seem to get rid of them. I'd like to hear some ideas.

 

[Nano sapiens]

I had this issue for nearly a year on a smaller 7 year old tank with a DIY LED array. I tried everything from nutrient manipulation to salt water brand changes ...no luck. A few months ago I radically changed my DIY array from 2 to 5 channel and put 'Green' (Lime, Cyan) and 'Deep Red' (DR) on their own individual channels.

What I've found over the last few months is that by manipulating just the 'Red' channel I can directly control the amount of 'diatoms?' on the sand bed. In my case, two DR LEDs set at 10% produces virtually no algae, whereas 20% produces quite noticeable amounts.

Reducing or eliminating the 'Red' spectrum may not solve all sand bed issues as there may be multiple causes, but it might be worth a closer look for those using a 'full spectrum' LED system.

 

[Avp]

I had this issue for nearly a year on a smaller 7 year old tank with a DIY LED array. I tried everything from nutrient manipulation to salt water brand changes ...no luck. A few months ago I radically changed my DIY array from 2 to 5 channel and put 'Green' (Lime, Cyan) and 'Deep Red' (DR) on their own individual channels.

What I've found over the last few months is that by manipulating just the 'Red' channel I can directly control the amount of 'diatoms?' on the sand bed. In my case, two DR LEDs set at 10% produces virtually no algae, whereas 20% produces quite noticeable amounts.

Reducing or eliminating the 'Red' spectrum may not solve all sand bed issues as there may be multiple causes, but it might be worth a closer look for those using a 'full spectrum' LED system.

My outbreak definitely got worse when I switched to full spectrum leds. I tried just running the blue, deep blue, violet, and uv and shut off the white, reds, and greens...unfortunately the diatoms still thrived.

 

[Nano sapiens]

My outbreak definitely got worse when I switched to full spectrum leds. I tried just running the blue, deep blue, violet, and uv and shut off the white, reds, and greens...unfortunately the diatoms still thrived.

What I noticed is that the diatoms can keep going for a week or two even after I reduced the Deep Red channel. I've also noticed that direct, or even strong indirect natural sunlight, can keep them going since it supplies the red spectrum.

As is true with many things in this hobby, one solution may not work for all circumstances.

 

[brandon429]

and don't forget that final tweak of hand removing all of them before you reassess changes. growback stoppage is different than mass removal after making a change, that hand removal component is powerful

 

[Avp]

I do get some indirect sunlight. I wonder if I should try to block it.

 

[Nano sapiens]

I do get some indirect sunlight. I wonder if I should try to block it.

Sure, can't hurt to try. You can also try removing the the top-most layer of the sand bed. Alternatively, you could try lightly stirring this top-most layer to break up the diatom conglomerations. Some of the loose diatoms will then get caught in the mechanical filtration (if you have this) and exported while others can be caught/injested by filter feeders.

 

[Avp]

I have been stirring the sandbed lightly every day too. It helps break them up, but unfortunately they do come back.

 

[Nano sapiens]

I have been stirring the sandbed lightly every day too. It helps break them up, but unfortunately they do come back.

If the tank is new, then they diatoms are normal and tend to subside over time. If the tank is established (at least six months old), then reducing the Red spectrum may help, but it can take some time to see improvement.

 

[quicksil328]

My tank is approx. 3 yrs old now. I am using ATI t5s and run them about 8hrs per day. I am at a loss right now. I am going to add a 2nd gfo reactor. Running one on my tank just isn't enough. Maybe 2 will do the trick.

 

[NanaReefer]

I've been battling this issues for over a year. Substrate is CaribSea Arga-Live Fiji Pink. Seems to get worse after a WC. Almost completely gone after switching from black box led to a Radion. Sent Radion in for upgrade and put old light back on. Brown stuff came back within 4 days.

 

[reefwiser]

http://www.advancedaquarist.com/2003/1/aafeature1
for Diatom's to stay around they need a source of Silica.
Check the water added to your aquarium from you Ro/DI unit to make sure it is removing silica.
http://www.drsfostersmith.com/produ...YMBgqgc20u4RelTcJ8Bcu-WNIDtnv68OLgaAvrh8P8HAQ
I use a high capacity DI resin on my RO/DI unit.
http://spectrapure.com/FILTERS-MEMB...r-DI-Cartridge-Non-Indicating-SuperDI-10-inch

 

[Avp]

I've been battling this issues for over a year. Substrate is CaribSea Arga-Live Fiji Pink. Seems to get worse after a WC. Almost completely gone after switching from black box led to a Radion. Sent Radion in for upgrade and put old light back on. Brown stuff came back within 4 days.

Wow. That sure tells you these things like a certain type of light. Mine got way worse when I switched from a Chinese led fixture to ai primes. Thought it might have been a coincidence. My corals are doing better but the algae got worse also.

 

[Nano sapiens]

I've been battling this issues for over a year. Substrate is CaribSea Arga-Live Fiji Pink. Seems to get worse after a WC. Almost completely gone after switching from black box led to a Radion. Sent Radion in for upgrade and put old light back on. Brown stuff came back within 4 days.

The amount of sand bed algae in your pic looks very similar to when I had my old 2 channel LED array running about 40% 'Deep Red'. Running 12% DR right now (same two DR LEDs) and they are now nearly gone.

From my observations of what I've seen posted thus far (all anecdotal evidence, but the best we've got to work with):

1. Changing nutrient levels typically has little effect (unless levels are are so low that other organisms suffer/die) - (my experience, too).
2. Most with this issue use RO or RO/DI and still have it (me, too).
3. After water changes, one often sees an increase in algae growth (my experience, too).
4. Some have reported that going for weeks/months without water changes has helped or even resolved the issue (have not ried this).
5. Reduction or elimination of 'Red' light has reduced, or eliminated the issue (my experience, too).
6. Reduction or elimination of direct or bright indirect natural light has reduced algae growth (my experience, too).
7. Changing salt mixes can effect algae growth somewhat, but for many there has been no change (used three different salt mixes, no noticeable change).
8. Stirring the sand bed eliminates algae for a few hours, but they typically return if illuminated (my experience, too).
9. Removal of top layer of sand bed algae eliminates algae for a few hours, but they typically return if illuminated (my experience, too)..

 

[Avp]

The amount of sand bed algae in your pic looks very similar to when I had my old 2 channel LED array running about 40% 'Deep Red'. Running 12% DR right now (same two DR LEDs) and they are now nearly gone.

From my observations of what I've seen posted thus far (all anecdotal evidence, but the best we've got to work with):

1. Changing nutrient levels typically has little effect (unless levels are are so low that other organisms suffer/die) - (my experience, too).
2. Most with this issue use RO or RO/DI and still have it (me, too).
3. After water changes, one often sees an increase in algae growth (my experience, too).
4. Some have reported that going for weeks/months without water changes has helped or even resolved the issue (have not ried this).
5. Reduction or elimination of 'Red' light has reduced, or eliminated the issue (my experience, too).
6. Reduction or elimination of direct or bright indirect natural light has reduced algae growth (my experience, too).
7. Changing salt mixes can effect algae growth somewhat, but for many there has been no change (used three different salt mixes, no noticeable change).
8. Stirring the sand bed eliminates algae for a few hours, but they typically return if illuminated (my experience, too).
9. Removal of top layer of sand bed algae eliminates algae for a few hours, but they typically return if illuminated (my experience, too)..

That's pretty much what I've experienced. One thing though...I've shut off my reds for a couple of months and it did nothing to help. Only thing I haven't tried is eliminating water changes. I may have to try that.

 

[quicksil328]

I read that sillicates are the issue and that I should maybe change my DI resin. My Resin isn't even 2 months old yet. I have a hard time believing it's exhausted already.