# Stuggling with Diatoms / Brown Algae in mature tank



## Golightly (Jan 14, 2011)

I've been struggling with Brown Algae on plants, glass and rocks in a mature tank. On the plants it's always the lower leafs that are affected. Rocks are just covered in it and instead of seeing the nice grey/purple colouration of the Manten stone it's just a brownish color (If I scrub the stones the brown algae comes off easily).

I have no other signs of any other type of algae except maybe a tiny amount of green spot algae on the upper parts of some wood that's just by the water surface. I expect that's because it's so close to the light.

The affected plants are mainly stem plants which are situated where the highest amount of flow is, they are all swaying in the current and got plenty of space around them. For some odd reason the larger plants in lower flow areas (Echinodorus) are not affected it seems.

I'm dosing daily with 8ml TPN+, 5x drops of ECA and 5ml Excel every other day. 

I have moved about some plants a few times over the last month, which each time has disturbed the substrate. 

Tank and Equipment:
- 170L / 50g tank
- 3 x AquaRay GroBeam 1000 ND LEDs (PAR reading at the bottom of the tank is around 80-90)
- Inline CO2 reactor
- Fluval G6 (2460 lph / 1000lgh) 

Values

PAR: 80-90
PH: 6.50
CO2: LimeGreen / Yellow
NH3: 0
NO2: 0
NO3: 10-20ppm
PO4 Tank Water: 0.3-0.4ppm
PO4 Tap Water: 1.8+ppm
KH: 12
GH: 18

I only today measured PO4 for the first time and noticed the huge difference between my tap water and tank water. Is there any chance that High PO4 in the water I put into the tank can cause this problem?

Or could it be that I have too low light?


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## Golightly (Jan 14, 2011)

*added some pics*

Took some pictures as example. Weirdly the stone to the right of the plants has some green algae but I think that's because I didn't clean it properly from my last tank as no other stones or anywhere else suffers from the same.


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## jl209 (Mar 2, 2006)

What kind of sand is that? If its silica sand you will have diatoms for awhile. I have silica based sand and it took about 6 months for the diatoms to die. Waterchanges help as long as you don't have silicates coming out of the tap.algae eaters own this algae get a few. Other than that its just a waiting game ime


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## Golightly (Jan 14, 2011)

jl209 said:


> What kind of sand is that? If its silica sand you will have diatoms for awhile. I have silica based sand and it took about 6 months for the diatoms to die. Waterchanges help as long as you don't have silicates coming out of the tap.algae eaters own this algae get a few. Other than that its just a waiting game ime


It's ADA Nile Sand, I thought it was supposed to be inert?

I've got some algae eaters: 3 x Oto's, 10 x Shrimps and a Apple snail.


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## h2oaggie (Feb 28, 2011)

I have the same problem and wish I could help. Currently have 2 apple snails, 7 oto's and 1 BN pleco in my 29 gallon and the diatoms are still smothering my plants.


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## jl209 (Mar 2, 2006)

I have no idea what that sand is composed of. Diatoms need silicates to form their skeletons. Without them you would have no diatoms. That sand is inert as far as nutrients are concerned. However there are probably silicates in it. Diatoms are common in the first 6 months of a tank setup. An algae crew would greatly reduce them.


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## Golightly (Jan 14, 2011)

Maybe most sands including the one I have contains silicates?

Are there other sources for silicates?

Is is only silicates + phosphates that diatoms thrive on?

What gets rid of diatoms except algae crew which I have?


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## wetworks (Jul 22, 2011)

Golightly said:


> Maybe most sands including the one I have contains silicates?
> 
> Are there other sources for silicates?
> 
> ...


I have used a Marineland Magnum 350 with the micron cartridge to remove any algae that is suspended in the water column. Would dosing Excel help remove it from your surfaces? Also, how would blacking out your tank work to remove it? Good luck!


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## jl209 (Mar 2, 2006)

The only other source for diatoms I ever hear about is through your tap water. You can call your local municipality and obtain a water report to see if that's your problem. Nutrients aren't your problem its the silicates. Honestly if your patient they will take care of themselves. My sand is pool filter sand which is 100 percent silica. Once it stops leeching silicates into the water column your diatoms will go away. A blackout might help but the diatoms will just come back if there are excess silicates in the water column. Its just one of those things have to be patient with.


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## CmLaracy (Jan 7, 2007)

has anyone ever heard of well water having silicates? My water column is 300 feet below the ground so the water is absolutely sparkling and delicious, like bottled water.

I also have a water softener.

I struggle with diatoms and I'm really starting to suspect it's the dissolved silicon ions. I've never had problems with any algae besides diatoms, and I do EVERYTHING there is to get rid of them. So they dont run rampant but they certainly slow growth.

Super high light tank. 6+wpg MH


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## 150EH (Dec 6, 2004)

Sand and Silicates go hand in hand don't they, and even if they didn't silicates settle in the substrate and can often cause a diatom out break when the substrate is disturbed.

I am the Diatom Master so don't even think of trying to steal my title, I try to reduce dosing and no water changes until the diatoms are gone, Otocinclus to the tune of 1 fish per 10 gallons. API makes a little DI cartridge and housing for around $45 with refills about $20 that is painfully slow but works and the idea is not to use it at every water change but try every other or every third and try not to disturb the substrate too much or just vacuum lightly to get fish waste without inserting anything into the substrate. I just bought a 6 stage RO/DI unit from Bulk Reef Supply so after 7 - 8 years of nasty film on any rocks, substrate, plant leaves, I will have clean water soon but I just need a few more bits to finish the system.

Yes, well water can be loaded with silicates what better candidate with no type of processing at all, and my theory is the closer you are to the shore line of some type of salt water the worse off you are. I can throw a stone right now and hit the Chesapeake Bay. I also have a water softener and this one is fairly new and supposed to use the salt pellet in the brine tank but I find if I use the salt crystals mixed with iron removing pellets I can get a 0 gH and 4.48 kH and my test equipment is less than perfect but if it's even close that's OK. Some of the older water softeners were bad and the brine was not rinsed from the resin well enough, they are basically big DI units that are regenerated after a certain amount of water is used, another problem with the old ones was it regenerated after a period of time had elapsed.


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## CmLaracy (Jan 7, 2007)

SO! I figured it out. We have very sandy soil, it allows us to have a septic. The rain water that gets filtered through the sand ends up in our well.

Looks like I need an RO/DI filter. Shoulda known when 50% daily WC's doesn't kill the diatoms after a while... I'm actually FEEDING them.

2 scapes of mine have failed due to diatoms. This has to be the reason. Theres not another algae out there that gives me problems or ever even crops up.

So I should look to spend around $200 so I don't buy a POS?


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## Golightly (Jan 14, 2011)

CmLaracy said:


> has anyone ever heard of well water having silicates? My water column is 300 feet below the ground so the water is absolutely sparkling and delicious, like bottled water.
> 
> I also have a water softener.
> 
> ...


I've had very little diatoms since I lowered my lights to around PAR30 (reduced it from high light / PAR90). So if you have a lot of silicates in your water + high light it will mean you get diatoms. But with lower light you might not have any. Plants seems fine. I guess the thinking is that if you limit light but have enough of everything else it might work better with less algae.


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## CmLaracy (Jan 7, 2007)

Golightly said:


> I've had very little diatoms since I lowered my lights to around PAR30 (reduced it from high light / PAR90). So if you have a lot of silicates in your water + high light it will mean you get diatoms. But with lower light you might not have any. Plants seems fine. I guess the thinking is that if you limit light but have enough of everything else it might work better with less algae.


good thought, but I'm just going to take the silicates entirely out of the equation I'm sick of this bacteria.


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## Golightly (Jan 14, 2011)

It's very difficult to remove silicate entirely. I tried that first. Tested several Phos/Silicate removers, they had very little difference. Even now when I use 2/3 RO water there is high levels (trying to get Rams to breed). Even RO doesn't remove all of it.


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## AUAV8R (Jul 7, 2010)

I've had diatom problems for over a year. Low light... high light, it didn't matter I still had diatoms. I finally realized that my tap water must be the culprit so I reduced my water changes, the amount of food I feed my fish, and started using a phosphate removing pad in my filter. I have seen a significant decrease in diatoms but haven't eradicated them completely.


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## jocky (Feb 14, 2010)

CmLaracy said:


> SO! I figured it out. We have very sandy soil, it allows us to have a septic. The rain water that gets filtered through the sand ends up in our well.
> 
> Looks like I need an RO/DI filter. Shoulda known when 50% daily WC's doesn't kill the diatoms after a while... I'm actually FEEDING them.
> 
> ...


I think you should try to use a lower source of lighting before you invest in such a spendy unit. I had my 150 watt MH over a 29 gallon and my plants were brown through and through. I had recently switched over to a 96 watt compact and my diatom has disappeared. My plants have been recovering for about 2 weeks now and have grown bright green and red shoots lately. They are growing a lot slower compared to the MH but they aren't covered in algae.
This is what I have found to solve my problem, I just want to pass it along.


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## kilfrg7864 (May 7, 2010)

I have the same problem. I think that they are coming from my weekly water changes. The problem is im not sure if i can reduce the water changes with EI dosing. Anyone have any insight on this?


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