My experience with overdosing Metricide 28 (Fluorish Excel, glutaraldehyde) for algae.

Oughtsix

Redtail Catfish
MFK Member
Apr 9, 2011
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Redmond, OR
My 180g dirt bottom planted aquarium has been cycling for about 3 weeks now. IT HAS NO FISH IN IT!

Although I have other aquariums and plenty of mature bio media to harvest I opted to do go for a slow startup. When building the dirt bottom of the 180 I used a fair bit of dirt out of our mature (several years old) 35g planted tank to supply some starting bacteria to the dirt. I added mechanical filter media (sponges and floss) squeezings as well as a large sponge filter from another tank to introduce some nitrifying bacteria. Water tests showed that my 180 was fish worthy after about 9 days. Household ammonia added to the tank disappeared in about a single day and Nitrate levels went up. I never had any significant nitrite readings.

I went whole hog on the dirt for the 180. I used Miracle grow potting soil, Mississippi red clay, crushed red lava rock (from my driveway), volcanic soil (from my back yard), Aragonite sand, Sphagnum peat-moss, Azomite for trace minerals, Dolomite Lime, Potash, horticultural carbon, Medium (~6mm) gravel, Amazonia soil, Amazonia powdered soil and a little black blasting sand. The deepest substrate is about 5" (about a single inch deeper than our 5yo 35g planted tank). I put the most active materials on the bottom and built up with a layer of the horticultural carbon as a buffer between the more active and less active ingredients. I chose a darker medium river gravel as my cap layer and sprinkled the Amazonia, Amazonia powder and black blasting sand on top of the gravel to give the plants a bit finer top layer to grab onto. These ingredients kind of fell into the gaps between the medium gravel.

I heavily planted the 180 before filling it with Dwarf Hair Grass, S ripens, Ludwigia Repens , Amazon swords, miniature Anubias and a couple others. In a lot of places I had to add some little piles of Amazonia soil to keep the Dwarf hairgrass in place.

I immediately started blasting the poor tank with very high light and VERY heavy CO2. I am using a fan type powerhead to push a good amount of circulation through the tank. Within 3 days I had an expected brown algae (diatoms actually) powdery layer on everything including the plants. After another couple of days I had green string algae starting to develop. I added a cleaning crew of a couple dozen rams horn snails. After another day the green powder algae started to develop on the walls of the tank.

At this point I added the first dose of Metricide, 2ml. I waited 2 days and the algae was thicker.

I added 10ml of Metracide. After two more days the green string algae was getting a pretty good hold on the tank.

I did a 100% water change then added 25ml of Metricide. After 2 more days the brown algae (diatoms) seemed to not be getting any thicker. The Ludwigia Repens was pearling heavily and seemed to grow very vivid new growth of about an inch in 2 days. The s ripens weren't doing much. A started knocking off the diatoms from the Dwarf Hair grass with a stick.

I added 50ml of Metricide. In the next two days the green algae seemed to be leveling off a bit. The rams horn snails were growing noticeably on the algae rich tank. The s ripens and Anubias seemed to start taking hold and showing the first signs of new growth bugs. The Ludwigia Repens grew at least another inch. So I let the tank brew for a couple more days at which the green string algae wasn't growing or spreading a lot but wasn't disappearing.

I did another 100% water change and added 100ml of Metricide. In 2 days the green string algae was starting to turn brown. The rams horn snails laid egg clusters all over the sides of the aquarium and the first signs of life from the Dwarf hair grass appeared.

I add 50ml more Metricide and let the tank sit another 2 days doing nothing but knocking off dyeing algae and diatoms from the plants and rocks which brings me to today. The tank is noticeably clear of algae. The snails are even bigger. The Dwarf Hairgrass is starting to send out some runners and new blades are popping up close to where they were originally planted. The Ludwigia Repens have doubled in size. The Anubias is starting to put out new leaves. The S Ripens is adding several new leaves and growing (It seems to be growing up instead of spreading). The Amazon swords have shed most all of their original leaves and have a healthy growth of new leaves. The clear rams horn snail egg clusters are starting to develop little black spots. My DE filter is noticeably plugged and starting to slow down even after regenerating the existing DE... I think I am going to have to change the DE.

I have about 3/4ths of the tank hardscaped and planted. I had a little setback when my rotary hammer died and I was no longer able to make cap rocks for the bottom returns. When the new motor brushes come in next week I will finish drilling the basalt rocks to be return diffusers and finish up the hardscape and the planting. I am hoping to add fish in another week or two.

My take (you are welcome to come to you own conclusions) is heavily dosing Metricid is effective at killing off Green string Algae and Green powder Algae. Rams horn snail seem oblivious to the heavy concentration of Metricide as do the plants. I am a definite believer in bringing up a new planted tank and holding off on adding fish until the inevitable algae battles are mostly over with. I am also a very big fan of Rams horn snails!
 
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Oughtsix

Redtail Catfish
MFK Member
Apr 9, 2011
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553
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Redmond, OR
MetriCide 28 is a 2.5% glutaraldehyde concentration --which is what I am using
MetriCide 14 is a 2.6% glutaraldehyde concentration
Seachem Excel contains a concentration of 1.5% glutaraldehyde.

So Metricide 28 is 1.67 times stronger than Excel.
Metricide 14 is 1.73 times stronger than Excel.

My tank is 180g. My sump is 55g. I estimate my total actual water volume to be about 200g.
 
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FreshyFresh

Peacock Bass
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Very cool findings.

What lighting are you using over this tank?

I was into the Metricide 14 thing some years ago after tiring of buying $ bottles of Excel and other "liquid CO2" products. I may still have some left. Got blasted plenty by people that have been in the hobby longer than I that this stuff is "poison" and "nothing to mess with" and it wasn't the same as the other aquarium specific liquid CO2 products.

These days I don't add any form of CO2 or any ferts to my tanks with plants. The tanks are 8+ years old w/ ordinary gravel that I don't gravel vac. The plants I keep are basic cyrpts, java fern, different types of anubia, some swords, etc.
 

Oughtsix

Redtail Catfish
MFK Member
Apr 9, 2011
1,600
553
150
Redmond, OR
My local Costco had the following LED shop lights on sale and the local electric company had an instant rebate (at the cash register) that made them less that $20 per light (~$15 maybe, I forget). I bought several of them to replace the old fluorescent fixtures in my shop... but I haven't hung them yet. I just tossed 4 of these on top of my tank. They easily light up the whole top story of my house all by themselves. When I finish my DIY LED light tailored to aquatic plants these will go in my shop.
LEDShopLights.jpg

My old low-tech 35g tank is a dirt bottom with gravel cap. No ferts, no CO2 and no glutaraldehyde. I am quite pleased with it. I wanted to try a Dwarf Hairgrass carpet this time hence the CO2 injection. I already had everything to add CO2 to my tank so it didn't cost me anything. I am thinking about weaning the tank down to low-tech eventually once everything is established and growing strong. I am not sure how that transition will go. Currently the Ludwigia Repens are growing so fast that I can't see myself wanting to trim them on a weekly basis to keep them under control. I will just have to see as the tank matures.

I have read tons of posts about glutaraldehyde, Excel and Metricide on the internet with all sorts of conflicting information. I have had new planted tank algae battles in every past planted tank. This time I was ready for it and prepared. The Metricide was like dropping a nuclear bomb on the Algae. At this point I don't think I will be dosing glutaraldehyde long term. But I will probably end up going with what ever gives me the results I want.

I found so few detailed accounts of using glutaraldehyde for algae control I figured it might be helpful to someone in the future to do so. :)
 
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