# lazy algae eaters?



## Acorn27 (Sep 1, 2009)

So what's the deal with my plecos? I have a BN pleco (~ 2-1/2") and another pleco (~ 3") and I hardly ever see them taking care of any algae. They have been in the tank for about 3 weeks and the algae is really spreading over everything. Both brown (diatoms?) and green algae are everywhere. I also have 9 nerite snails that don't seem to be doing much either.

Are they getting another easier food source?
Are they afraid of the other fish? (mbunas, syno petricolas)
Are they eating the algae at night when the lights are off? Doesn't seem like it.
Are they just lazy?

I'm going to measure the phosphates because I understand if that is high the algae growth will be more prominent. Maybe my phosphates are so high that I'm loosing the battle?


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## DJRansome (Oct 29, 2005)

I don't think either BN or nerites are best known for eating diatoms, but they should put a dent in the green algae.

IME both are best on the glass but will do some decor cleaning if all the other algae is cleaned up already.

My nerites did not last with mbuna. Kept getting knocked off the glass and landing upside down. Not too swift at uprighting themselves, I did it daily but I think they eventually starved.

How big is the tank? How many of each do you have? Was the glass scraped clean when they first arrived and they have not been able to maintain? Do you see their track-marks through the algae on your glass?


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## Acorn27 (Sep 1, 2009)

It's a 90 gallon tank. 2 plecos and 9 snails. THe other fish are in my signature. I have scrubbed the glass several times, and scrubbed off the rocks once or twice. The green is not really growing on the glass, just the diatoms. But there is a good crop growing on the flat limestone and flagstone rocks I have in the tank. Should be easy pickins for those guys. I always heard that the BN plecos were the best at cleaning up algae. Maybe the one I got is a dud? :zz:

I've had the snails for a couple of months. They are cool and hanging in there. I just wish they would pull their weight a bit more.... :lol:


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## DJRansome (Oct 29, 2005)

My BN did pretty much nothing with the rocks. I had them a while before I got the nerites. The nerites too prefer the glass but will go to the rocks if the glass is clean.

Try putting the nerites on the rocks periodically. They will eat their way across at least, LOL.

I think you are stuck waiting out the diatoms. They go away by themselves eventually.

Many consider algae covered rocks desirable.


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## Acorn27 (Sep 1, 2009)

Speaking of diatoms, I read that high phosphates in the water can lead to diatom and excessive algae growth. I picked up a phosphate test kit today that I'm going to try in a little while. If they phosphates are high I guess I can do a couple of things to help control that, one is using a poly-filter in the canister media container.

If my water supply contains high phosphates, every time I do a water change I will add more to the tank, so in theory it won't go away. I may have to battle this forever.

We'll see what the test kit says a bit later.


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## Acorn27 (Sep 1, 2009)

I just checked the phosphates in the tank with a dropper test kit:

Current reading in the tank is approx 3 ppm.
Tested tap water and it came out at approx .25 ppm.

Does this mean my tank is dirty? Am I overfeeding? I do a 30% - 50% water change weekly and vacuum as much of the gravel as I can get to.


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## DJRansome (Oct 29, 2005)

Acorn27 said:


> Does this mean my tank is dirty? Am I overfeeding? I do a 30% - 50% water change weekly and vacuum as much of the gravel as I can get to.


Maybe. What are your nitrates?

Try feeding 25% less and upping your water changes to 50%. You should be able to get to ALL the gravel because: 
there is none under the rocks...you put your rocks in before the substrate.
if there is some in a crack where the python won't fit, use a turkey baster to blast the spot and catch the debris by hovering with the python
be sure to blast between the rocks with the turkey baster as well during PWC

When I did the same test I had zero phosphates tap and tank. But literature states phosphates in the tank are due to organic materials.


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## Acorn27 (Sep 1, 2009)

Nitrates are 0.

I pondered for a while and I'm thinking I might be over feeding. That is a 'rookie' mistake so I'm going to cut back to feeding only once per day. How do you know if you are starving your fish? I guess with mbunas if they get hungry enought some of them will start grazing on the green algae, huh?

I'll continue with teh 50% weekly water changes, and try to get more of the debris vacuumed. I have lots and lots of cave structure in my rocks, and there are several hiding spots where rocks make a 'bridge' over the gravel, which means I can't easily vacuum that spot. The turkey baster is a good idea.


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## DJRansome (Oct 29, 2005)

Once a day is plenty for mbuna. You know you are starving them if their bellies start to sink in a little. But it's odd that you would have phosphate and zero nitrate. Do you have plants? How did you cycle your tank?


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## Acorn27 (Sep 1, 2009)

No plants. I cycled the tank like a rookie, a little quickly. I cycled the tank fishleses at first. I added a very large driftwood right away which I purchased from a local fish store (thought that might have some bio in it) and shook & rubbed out the HOB filter from my 30 gallon next to the bio wheel. After about 9 days I put a big pleco in to start creating some ammonia etc. I figured he'd be tough enough to take it, and start the live cycling. So about 3 weeks of fishless/live cycling mixed. But everything worked out I guess becuase it has been running since early August.

Maybe I should use the dropper test kits for nitrate/nitrite/ammonia, now I'm just using the test strips.


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## DJRansome (Oct 29, 2005)

If you have no nitrates it is unlikely your tank is cycled. What is your ammonia and nitrite?


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## Acorn27 (Sep 1, 2009)

I'll need to check readings again.

Is it possible to have fish in a tank for over three months and it not be cycled?


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## DJRansome (Oct 29, 2005)

Yes but you would have ammonia readings at least and nitrite readings probably as well. It takes 6-8 weeks to cycle a tank if nothing harms the bacteria during that time. And did you add all your fish day one, or over time?

Nitrate is the waste generated by healthy bacteria. So...no nitrate, no healthy bacteria. Unless you have plants that are eating it all up, LOL. I have heard of people having algae that consumed a large amount of nitrates, but that has not been my experience.


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## ollie78 (Jul 23, 2009)

The diatoms are best taken care of by waiting them out. Last tank I set up it took 4-5 weeks for the diatoms issue to go away. 
I personally like the green algae growth on my rocks, adds that natural look.


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## Acorn27 (Sep 1, 2009)

Tonight I checked ammonia with a new dropper test kit, reading was 0.
Nitrates and nitrites were also 0 (test strips).

I last did a 50% water change 8 days ago. Typically I do around 50% weekly. So either the tank is fully cycled and the water conditions are working, or my large % water changes are preventing me from getting any readings on waste byproducts.

So the phosphate reading and fighting diatoms for 3 months is probably due to overfeeding and maybe not vacuuming under the rocks good enough?


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## DJRansome (Oct 29, 2005)

You still need to have a nitrate reading, something is not right. Either the test kit is not working, or the tank is not cycled.

50% weekly water changes will not keep nitrates at zero. If nitrates were zero you probably would not have algae either (no nutrients for it to grow).

Diatoms are normal in a new tank. Excess algae is due to excess nutrients, whether it be food or nitrates.


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## Acorn27 (Sep 1, 2009)

The nitrate test strips were new in August. It's an API multi-test strip for kh, gh ph, nitrites and nitrates. I keep the container sealed at all times. I'm assuming they are OK unless there is a mfg problem. When these are used up I'll get a complete dropper test kit.

Would it make sense to NOT do a water change until I see a nitrate reading? I could test ammonia levels daily to keep an eye on that. I guess the risk there would be the presence of nitrates that my kit is not measuring if somethign is wrong with it.


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## DJRansome (Oct 29, 2005)

I don't know what to tell you. I like to keep my nitrates between 10ppm and 20ppm which works perfectly with weekly 50% water changes.

I would not stop your 50% weekly water changes. Your algae would probably get even worse.


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## goldoccie21 (Jun 15, 2008)

otocinclus catfish, and most fish will not bother them. a group of 7-10 will eat all the diatoms over night. and also their impact on the bio load is minimal.


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## Acorn27 (Sep 1, 2009)

Well I did a thorough cleaning & water change and removed all the driftwood from the tank.

Hopefully that will cause the plecos to stay off the wood and take better care of the rocks & glass.


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## Acorn27 (Sep 1, 2009)

Well, I removed the driftwood completely and things have changed quite a bit. The plecos are much more industrious at taking care of the algae. I also cut down a lot on the feeding in general which has seemed to result in fewer diatom growth as well. Nitrates are pretty much zero.

I've come to realize that the nerite snails just don't work with the fish I have. I think they get harassed too much and I've had quite a few die.

I have a brown BN pleco, and one of these guys. Anyone know what species he is exactly?


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