Algae/Diotomes, I want to cry!

[fishfanatic]

For the whole life of my 20 gallon tank (about 3 months) I have had constant algae/diatom problems. I am almost certain it is diotomes. It is a dark green color and it grows like a blanket over everything. When I scrape it off the glass it kind of peels up. It has managed to cover all the plants in the tank, even the floating plants roots. As you can imagine the plants are suffering greatly.
Here are the specs of my tank:

• T5HO duel hagen glo light fixture (one 18000K bulb and the other 5000K) I need new bulbs I know...

• 20 gallon long tank

• 100 watt aqueon heater (don't know why I included this)

• AquaClear 50 (with sponge, poly fill, and biomax)

• Petco black sand (petco brand)

• Ammonia 0, nitrIte 0, and nitrAte 20

• Tank live stock: 2 adult kribinsis (pair) and 5-10 baby kribs (about a 1/8 inch long)
• I do a 50% pwc every 2 weeks (using prime as a water conditioner)
• I used to add flourish comprehensive once a week but stopped about a month ago.

The first problems that stand out in my mind is the light bulb kelvin range and the petco sand.
Is it possible that the sand is leaking silicate into the water (I read that silicate can cause diotomes)?

Is there some kind of silicate remover that I could put in the filter for a few weeks?

Thanks for all your help and time!
Here are some pictures of the green monster growing on some java moss (well what was java moss):

 

[Chiroptera]

Diatoms are usually brown, you may just have algae.

I'd just recommend getting a pleco. If you have it now, it will come back, and dosing things can be a pain once it all adds up.

I had a baby pleco in a 10 gallon (which, by the way, is too small for any pleco, but I use it as a nursery (for baby fish) and QT tank) and it removed CAKED diatoms in just a few hours. It's totally worth it. But yourself a Bristlenose pleco, and you won't be dissapointed.

 

[blert]

That's not diatoms. Two T5HO bulbs on top of a twenty gallon is a ton of light, that's the problem. Cut your lighting period way down or moderately plant the tank and add DIY CO2. The need for CO2 injection is nearly a given when using T5HO.

 

[Bottomfeeder88]

You have Cyanobacteria. The good news there's meds you can use to rid these colonies, but to avoid reoccurrences you'll need to limit the amount and/or duration of lighting, and maybe add water movement and oxidation.

 

[fishfanatic]

Oh I failed to mention that my lite is mounted 10 inches above the tank. I could ease it as high as I need (limit of 46 inches). Should I move the light up higher? How many hours a day should the light be on for? 6 hours?
What kinds of medication will help this infestation?

 

[Bottomfeeder88]

10" doesn't sound bad I'd start at 6 hrs. BGA as cyano is called and diatom are common in new tanks with medium+ lighting IME.
Erythromycin targets gram negative bacteria. If you go that route just follow the instructions on the box. You can find it in most pet stores in the fish med area.

 

[fishfanatic]

I could add co2 to the tank. I have a pressurized co2 system in that room all i would need is a diffuser. The down side to that is it will use a lot of co2 with the HOB filter off gassing it all. Before I try co2 I am going to shorten the photo period to 6 hrs and see if it can solve the problem more naturally. I don't think the medication would be good for my baby kribs. I also went out and got some 6500K bulbs (instead of the 5,000K and 18,000K) I think this will help a little. I might take out the plants and spot treat them if you will. I would put them in a bucket and treat the bucket with Erythromycin.

Thanks for everyone's help!!! I will keep you all posted how the decreased light period goes. I don't expect to see results for a few weeks. Thanks again!

 

[blert]

The Kelvin temperature is for your viewing pleasure, so long as the bulbs are full spectrum (for plant growth) it is not really relevant. If the bulbs were pushing a year old that is another matter and you did need new bulbs. Shorten your photoperiod and raise those lights a bit until the mess is under control. Extra aeration will help as will making sure there is adequate flow in the tank (as previously mentioned). Bumping up your water change schedule for a while will help also.

 

[mohican]

That's not entirely true. Plants will thrive at certain k scale and so does algae. Finding the right k scale for individual tanks is what makes the hobby unique because we each have a certain "k" value(s) that work for each tank. Typically, plants thrive at a basic 6k, (+/-) range.

 

[blert]

Kelvin temperature is the color of the light YOU see, not what the plant or algae sees. A full spectrum bulb at 3000K will grow plants the same as a full spectrum bulb at 6500K, it will just look very yellow. Same with a full spectrum 10000k compared to a 6500k, it will just look much whiter. A Full Spectrum bulb is what matters. Old bulbs can have a shifted spectrum which then results in poor plant growth and algae issues.

If your 18000K bulb (quite bluish) was not full spectrum that might have contributed to the problem.

 

[mohican]

IMO, Not to argue case and point, but k value makes a difference in what we keep in our aquariums, from freshwater to saltwater. K value does more than just visual effects to human eye, it serves purpose in growth, from algae, plant health and coral growth.

http://www.peteducation.com/article.cfm?c=16+2151&aid=2689

 

[blert]

With deepest respect to you Mohican, we will just have to agree to disagree. I gotta point something out to you concerning the article you posted though...
"The commonly used unit to measure the spectrum or "temperature" of light is called degrees Kelvin (K)." (second paragraph, I think)
That statement is incorrect. Color temperature is not indicative of spectral distribution.

Anyway, I'll stop with the thread hijack now.

 

[fishfanatic]

Well ether way, the bulbs were over 2 years old... I personally believe that kelvin does matter, in the past I have had sever algae problems due to in correct kelvin ratings. But that is not what this thread is about.
I am going to do 50% pwc twice a week to help get things nice and balanced. I will post an update if there is a change in the bga.

 

[fishfanatic]

I decided to get some medication to treat some of the plants. I chose API E.M. ERYTHROMYCIN as my weapon of choice. So as of now I have my Christmas moss and Phoenix moss in a bucket that is treated. Depending on how well that goes I may treat my floating plants.
The lady at the fish store suggested that more surface movement might help she said low oxygen levels can contribute to BGA as well as over feeding and lighting.
Would adding an air stone be beneficial? I assume it wouldn't heart anything?

 

[aqua_chem]

The lady at the fish store suggested that more surface movement might help she said low oxygen levels can contribute to BGA as well as over feeding and lighting.

That's actually pretty solid advice. We don't really know the root causes of many algaes for sure, but it has been proposed that there is a relationship between poor oxygenation, high organic content/poor tank hygiene, and light. What kind of filter do you have on the tank right now? I personally think that airstones are unsightly and largely unnecessary in most setups.

Hmm, so you're separately treating your plants? I don't really see the benefit of doing that. You generally just want to treat the whole tank according to the directions on the box.

 

[fishfanatic]

That's actually pretty solid advice. We don't really know the root causes of many algaes for sure, but it has been proposed that there is a relationship between poor oxygenation, high organic content/poor tank hygiene, and light. What kind of filter do you have on the tank right now? I personally think that airstones are unsightly and largely unnecessary in most setups.

Hmm, so you're separately treating your plants? I don't really see the benefit of doing that. You generally just want to treat the whole tank according to the directions on the box.

I have an aqua clear 50 with the standard filter sponge, poly fill, and Bio media.
I agree that air stones are unsightly.

I am hesitant about treating the tank, I don't want any side effects such as harming BB. At this point I was thinking I would try to save the plants (they are completely covered in BGA).

If you guys think the BB and baby Kribs will be unharmed from the medication then I will treat the whole tank.

 

[aqua_chem]

Your biofilter would be unharmed. Your baby Kribs on the other hand, I'm not sure. It's outside my realm of experience. I will say that some people do observe a small spike in ammonia when treating BBA with antibiotics, but it's a result of the massive dieoff of the cyanobacteria rather than an adverse reaction with the biofilter.

You should have OK oxygenation with the HOB filter, assuming you aren't taking steps to dampen the surface agitation. More waterchanges in the future might be beneficial.

 

[fishfanatic]

You should have OK oxygenation with the HOB filter, assuming you aren't taking steps to dampen the surface agitation. More waterchanges in the future might be beneficial.

I have done something that might be dampening the surface agitation. I have put a "cage" around the outflow to stop my floating plants from being pushed under water. It isn't stopping/slowing the water from hitting the surface but I probably does decrease the water movement in the tank. Here is a picture of what I did, it is that plastic knitting stuff that you get at craft stores that has square holes in it.

The app won't let me post a picture so I will post one in a minute when I get to a computer...

 

[fishfanatic]

Okey here is the picture...

The mesh goes a few inches down into the water as well.

 

[sudz]

How did this work out for you? I am having the same problem. Discus tank with huge bloom, since I started with my LED lights and dosing Flourish Excel regularly. I've got it down to a 5 hour light cycle, but definately need to treat. I've JUST bought a CO2 system (assuming the deal goes through on Kijiji) so hopefully that will help me prevent in the future.