Removal for Some Algae, Thriving for Others

For some reason (probably nutrient related), the temple on the left-hand side has just been getting decimated. The leaves and stems have been turning brown and flimsy and basically disintegrating, so I have gone from having too much to not enough of it. I cut off the healthy looking tops of a few whose bases had decayed and I tried to locate and remove all the rotted bits. I'm hoping the replanted plant tops will put down roots and try again.

Additional problems include a nice algae film covering the bottom of the tank and choking out the hairgrass. It's even growing on the rotala indica when it's closed up for the night and preventing it from reopening in the morning. I believe it's blue-green algae (cyanobacteria) and one article indicated it was caused by excessive nutrients and waste. Sure enough, when I checked nitrates, they were off the charts! This is a tank the previously read less nitrates than the tap water! So, while it initially helped curb the hair algae, the ferts I added were obviously too much for the tank to handle, and I've accumulated far too many nitrates.

The neons I had been keeing in the 5 gallon have never really thrived, and recently when I checked on them, I noticed their numbers had dwindled to three (from six). I decided enough was enough, so I moved the three remaining neons to the bucket (nitrates in there were only 20 ppm). Hopefully they will feel a little safer there, and the bio-load in the 5-gallon will be reduced.

Slash and Burn... Well, Slash

I did some re-reading of case studies that looked at what the root causes of algae are and what to do about it. There conclusion was that for whatever reason, if phosphates were the factor limiting plant growth (as opposed to nitrates, light, CO2, etc.), then plants would outcompete algae. Now I thought I tried this earlier, but I think CO2 has always been one of my biggest limiters. That's why it helped when I first started adding Flourish Excel.

Now that I'm successfully injecting CO2 in the system (I got the pH down to ~7.4), I can prevent any other nutrients from limiting plant growth by resuming the Kent fertilizers (they're phosphate free). In this way, I hope to actually starve the tank of phosphates so that any that are produced are consumed by the plants. I got a phosphate tester and they are already quite low (nearly if not quite zero), so we already have a head start. I'd like to get an iron tester to make sure we're near the recommended 0.1 ppm. I considered getting Flourish potassium fertilizer, since a website that was based on the conclusions of the two case studies indicated high potassium levels will not promote algae. But Kent Freshwater Plant fertilizer has potash, so I'm hoping that will be sufficient.


I was sick of looking at all the besieged plants, so I hacked through most of the dying and/or algae-covered leaves so that the tank is actually looking pretty baren right now. I can only pray that I have really fixed the water chemistry and not crippled some of my ground plants by trimming down to a couple of leaves that will soon be overtaken by more algae. The ground plants were hacked down to the fewest leaves, but the greatest casualities were the foxtail and the rotala indica.

It Seemed Like a Good Idea at the Time

I went home over the weekend for a school reunion of sorts, but I also wanted to take care of some aquatic business using my dad's wide selection of power tools. I was able to cut a hose-sized hole out of the top of my small vacuum. Additionally, I drilled a hole through a bottle cap as part of my plan to upgrade the CO2 production to a full 2-liter bottle.

However, when I brought my new contraption home, I came to several realizations. First, the sponge was enough to choke the flow and create the noise I was trying to avoid. Second, the vacuum was so narrow that the bubbles didn't have a chance to escape and churn; instead, they were swept by the still powerful flow down the tube and out the sponge. So it looks as if I will have to stick with the bigger vacuum. Of course, it is still too long to point down, so I will have to take it back home and cut it down on another weekend.

In order to keep the downward flow from blowing up a lot of substrate, my plan is to "cap it off" with half a cylinder that will redirect the flow up and around the downward facing tube as well as keeping the sponge inside. I will have to improvise using either the bottom of a water bottle, the cap to a spray can, etc. The fun never ends!