Mixing cory catfish to help eliminate algae?

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sdrone

Aquarium Advice Regular
Joined
Oct 13, 2010
Messages
70
Location
Chicagoland, IL
After an incident recently in which 4 of my 5 tiger barbs died within about 36 hours (I think it was my gourami who finally got tired of them) I'm going over ideas for re-stocking my tank.

I'm down to:
1 gold gourami (big, but kids love this fish and have named it)
1 tiger barb
3 albino cory catfish

I know corys like schools, and over the last month I've started having a lot of algae, so I was thinking of getting another catfish. Would an emerald green cory mix OK with the albino cory? I think they are beautiful fish, though I'd have to try to find the smallest one in the tank since the ones the store has are pretty large - much larger than my albino corys.

The tiger barb seems ok alone - for now. He's more shy than agressive. I believe I'll get a school of red finned minor tetras; I talked my daughters into those rather than mollys, which I don't like.
 
I'm probably wrong here but my cory cats don't seem to bother with algae. I throw in a wafer for them now and then and they may pick at it but prefer their shrimp pellets. They don't adhere to the glass at all.. instead feeding off the bottom to keep excess food to a minimum. I'm sure they may consume some algae on the bottom while scavenging, but I have never noticed anything significant. I've also tried mixing the cory cats in the past, but for the most part they don't mingle too much. I ended up having 5 of each in the end. :)



After an incident recently in which 4 of my 5 tiger barbs died within about 36 hours (I think it was my gourami who finally got tired of them) I'm going over ideas for re-stocking my tank.

I'm down to:
1 gold gourami (big, but kids love this fish and have named it)
1 tiger barb
3 albino cory catfish

I know corys like schools, and over the last month I've started having a lot of algae, so I was thinking of getting another catfish. Would an emerald green cory mix OK with the albino cory? I think they are beautiful fish, though I'd have to try to find the smallest one in the tank since the ones the store has are pretty large - much larger than my albino corys.

The tiger barb seems ok alone - for now. He's more shy than agressive. I believe I'll get a school of red finned minor tetras; I talked my daughters into those rather than mollys, which I don't like.
 
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Try some otocinclus cats for your algae - no less than 3 or 4 depending on the size of your tank - I have five or six in my 75's and they stay clean!
 
Or, before adding fish to control the algae, find out what kind of algae you have and the reasons you have it, then fix the cause of the problem.


Adding fish or chemicals to a tank to fix a problem that is usually something we caused or can control is one of my pet peeves. Like some people want to add corys to eat left over food. Well, don't over feed to cause left over food.
Adding fish to eat algae, which is usually caused by an imbalance in the tank isn't going to solve anything. Find the problem, cure the problem.


Freshwater Algae Types: An Illustrated Guide - Article at The Age of Aquariums - Tropical Fish

Algae control in the aquarium
 
What is your nitrate concentration?

More water changes can help decrease algae by removing its food (nitrate and phosphate). However, in my experience almost every if not every tank does need some sort of living algae control. My pick is bristlenose plecos. They stay relatively small, will do well in any chemistry (hard or soft water), will do well in any temp (from goldfish to discus), won't bother plants or any fish, and will eat almost every type of algae out there.
 
Plus I know a lot of people who keep their lights on all the time or the tank is near direct sunlight thus causing more of an algae bloom.

Usually it seems to be more of an overstocking issue. Definitely find out the cause. Otherwise you're just slathering it in band-aids. Especially since there was a large fish loss recently. Seems like something is slightly off kilter.

I like my cats because they just have a lot of personality. Doesn't hurt if they help out with other things, so long as it's not the sole reason.
 
My nitrate reading has always been 40; I've never been able to get it to zero according to the color chart. The day after Christmas, my nitrate reading was between 40 and 80. It's now back to 40.

The algae sprang up about a month ago, several weeks before I had any other problems. I assumed I was overfeeding, and cut down on the food even though it seemed impossible to overfeed. It was actually entertaining; the 5 tiger barbs would basically do a feeding frenzy at feeding time. The food wasn't gone in 3m, it was gone in 1m. I could feed them AGAIN 1m later and they'd suck down all the food.

I run the light 10 hours/day, from 1pm to 11pm. There is a window, but there's brush outside the window and it's the middle of winter.

I have noticed that the corys don't spend much time eating algae; the occasionally browse the plants (which are now covered in algae) and they love algae wafers (they swarm the 1 wafer I give them a day) but otherwise they just cruise the sand.

I should consider a bristlenose pleco, if only becasue the kids would love it. When I got this tank, there was a pleco but it was pretty big and I had to trade it in; the kids still talk about "the brown fish" and how it would dig in the sand with its tail. I'd just be worried that any placo would be too big.
 
What is the nitrate concentration of your tap water? That could be a significant source of nitrate. However, that is a lot, even if you have a lot coming from your tap.

What is your water change schedule?
 
Fully cycled tanks usually have some NitrAtes present regardless. They build up over time and are not really as bad as the NitrItes. Generally it should stay at about .20 ppm or below.

Any idea if you have any NitrItes or ammonia present?

The cause of the algae growth could be also the reason the fish didn't make it, as well.

When you do filter maintenance, what is your routine? Do you toss it often? What filter are you running(rating, gallons per hour, brand, sponge or preassembled carbon media)?

Do you use a gravel vacuum?

Sorry to be nosy, just hoping to pinpoint it.

As for the pleco, I'd even wait on getting a bristlenose until you can figure out a way to keep the NitrAtes down because any additional fish at this point are going to only intensify it.


My nitrate reading has always been 40; I've never been able to get it to zero according to the color chart. The day after Christmas, my nitrate reading was between 40 and 80. It's now back to 40.

The algae sprang up about a month ago, several weeks before I had any other problems. I assumed I was overfeeding, and cut down on the food even though it seemed impossible to overfeed. It was actually entertaining; the 5 tiger barbs would basically do a feeding frenzy at feeding time. The food wasn't gone in 3m, it was gone in 1m. I could feed them AGAIN 1m later and they'd suck down all the food.

I run the light 10 hours/day, from 1pm to 11pm. There is a window, but there's brush outside the window and it's the middle of winter.

I have noticed that the corys don't spend much time eating algae; the occasionally browse the plants (which are now covered in algae) and they love algae wafers (they swarm the 1 wafer I give them a day) but otherwise they just cruise the sand.

I should consider a bristlenose pleco, if only becasue the kids would love it. When I got this tank, there was a pleco but it was pretty big and I had to trade it in; the kids still talk about "the brown fish" and how it would dig in the sand with its tail. I'd just be worried that any placo would be too big.
 
I appreciate everyone's help, let me see if I can address the questions...

I've never done a test on the tap water; I had it on my list of things to do and forgot about it. Now that you've reminded me, I will.

My ammonia reading has remained steady after I got the tank settled down at 0.25. It's often between the 2 yellow readings on the card, but I've never gotten the test bottle to exactly match the zero spot on the card. Nitrites are always zero.

Water changes: I have a 20 gallon tank and I vacuum out about 4 gallons every week.

Gravel vacuum: yes, that's what I use. I usually vacuum gently above the sand, and around plants etc. I try to remove water near the bottom.

Filter: I use an Aquaclear 30. I started with (from bottom) sponge/bio/carbon, but about 2 months ago switched to sponge/bio/sponge. After I vacuum out water each week, I divide the old aquarium water into 2 buckets. I rinse/squeeze/massage a sponge in each bucket, and rinse out the bio media.

Per recommendations on here, I have yet to toss any sponge media. I planned on replacing one of the sponges every 6 months or so.

I think one thing I may try is closing the blinds on the window near the aquarium a little bit.

Question: is 10 hours/day of light OK? What about 12 hours?
 
A quick web search gets me this about nitrates and reducing nitrates, which makes sense. It could be my tap water. I'll test it this afternoon, and I may have to go to using spring water or something like that.
 
Your idea of closing the blinds may help. I think the lighting is a factor here; the one tank I have in a very well-lit room with lots of windows, the tank initially had a lot of green algae on the glass facing the windows; I've set the light timer to give the tank an 'afternoon nap', say from 1 to 4pm. That cut down algae growth in this tank.

Cories won't control your algae. I have SAEs which will attack the algae (and other fish when they're cranky), and mystery snails eat it too.
 
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