Altivo

Black clouds intermixed with brief "sun showers". Never enough rain to count, sun never lasts long enough to matter. All outdoor things on hold.

Installed the DECnet for Linux packages and the features work just fine with the genuine Alpha hardware at the other end. Not so well with the emulated VAX, but this may be a configuration issue. It's rather like a dancing bear: It's not how well he dances, but the fact that he dances at all...

Fish tanks are still acting weird. The fish in the 30 gallon seem happy enough for the moment, but the pH of the water is way above 8.0 and that's too high. All the suggested treatments have failed to lower the reading. The 20 gallon tank (no fish) has the same high pH issue. Since there's no one in there, I've been experimenting by dumping quantities of white vinegar into it daily. No measurable result. The buffering capability of whatever is in that water is gigantic. The water is developing a white flaky sediment that doesn't dissolve but floats around like the flakes in a snow globe. I think it's probably sodium acetate, produced by a reaction between the sodium carbonate left in the water by our water softener and the acetic acid in the vinegar. The pH remains unbudged at around 8.4.

(Not with a bicycle, either.)

So this morning, about eight hours after reassembling the tank, it looked good. The fish were active, and quickly ate a little food when I added it. The pH had risen slightly, but was acceptable. Then an hour later, while we were eating breakfast, we watched the tank "bloom" with bacteria so quickly that it soon resembled milky water or household ammonia. Literally fogged up so you couldn't see the fish.

This is apparently a bloom of heterotrophic bacteria, the ones that usually break down organic waste and produce ammonia. Oddly, we have just removed huge amounts of organic material from the tank, so it is almost like new, and I didn't expect this.

Then when I got home from work, I found that the other tank, the one with no fish in it, has bloomed as well. Whatever we did, it stimulated these little bugs to go wild. They reproduce faster than you can replace the water, so changing water doesn't do much to stop them. Mostly you just have to wait them out. They have switched from anaerobic to aerobic metabolism, which means they can use up a lot of oxygen from teh water so we put the power head back in there to provide additional aeration.

It occurs to me that I could add some chlorine to the fishless tank to clear the bacteria, but of course it would take the good ones along with the bad, and that's not a desirable thing to bring about.

So we wait, watching the pH and ammonia levels and changing water if necessary to keep those controlled.

Whoa. I had no idea. Y'know, I've had fish tanks for a long time now. Something like half a century or so in fact. Tried marine environment once, but that is just too messy. Generally fresh water, easy stuff like live bearers, danios, and such. In the last 20 years I've finally begun to be aware of the complexity of water chemistry and how delicate the balance is. The idea that it could be actually controlled and corrected when it starts to tilt would have been incredible to me before that.

Anyway, we have one tank that has been going continuously for eight years. Not that it hasn't gone "sour" a couple of times in that period, because it has. But we'd just replace the water, clean out the filters, and bring it back to life. Then just recently we discovered that nothing we could do would bring the pH in that tank up to neutral. It stayed acidic, and would go all the way down to 6.0 in a week or so if left alone.

After seeking advice in multiple places we concluded that it was the undergravel filter, which had been running all those years. In theory, the power heads lift the gunk back up from under the gravel to where the filters and water changes can take care of it, but apparently they don't work that well and over time the space under the filter panels gets very foul indeed. This was the problem.

Today's advice is to remove the UGF completely, or else reverse the flow so that water is pushed down the tubes and under the gravel, forcing the gunk up through the substrate where it can be removed. So we decided to check it out. Moved the fish (seven swordtails of varying ages, and two plecostomi, one about eight inches long and the other quite tiny) into a couple of buckets filled with water from the tank. Took all the plants and rocks out, pushed the gravel to one side and started lifting out the plastic perforated panels of the undergravel filter. I have never seen such filthy water outside the foulest swamp. Black as pitch, filled with sediment, and even smelly. That was surely the problem.

Removed all the water down to the gravel and bare bottom. Replaced it with softened well water (not ideal, but the best we had on hand) and then added some pHDown to start pushing it down toward neutral as our well water is around 7.8 once it goes through the softener. It's also too soft, so I added "aquarium salt" to help compensate. The tank is now cycling through a clean filter element to remove the sediment that remains. Meanwhile, the fish are being slowly acclimatized to a higher pH by replacing a pint of water from each bucket with the softened well water every couple of hours. By tomorrow night I hope the conditions of the buckets and the newly-refurbished tank will match closely enough to allow us to return the fish to the tank.

One glance at the horror that is the radar composite of North America this evening and I can't but wonder whether Texas and Oklahoma are suffering a repeat of the super-tornado that ripped through Joplin, Missouri a few days ago. One hopes not, but it looks nasty.

Here we have light rain with occasional thunder. We need some rain, so I don't object.

One of Gary's new fish died today, and he took a water sample to the aquarium shop where they told him he had "high nitrates". My testing of the water shows nothing of the sort, but rather a low pH once again so we added some more buffering solution. The other tank, which has been devoid of fish for a year but had lush plant growth until last week when I removed most of it, has a high pH and does have a high nitrate level. That one has been topped up with treated well water that had been through our softener over the past year, and seems to validate my theory that the sodium carbonate residue of catalytic water softening provides a substantial buffering effect. I suspect we need to use a mix of unsoftened and softened water by drawing some off in the barn (untreated) and the rest in the house (treated.)

Penetrated the maze of missing documentation to get TCP/IP based printing working on my two VAX emulator installations. The discovery over the weekend that DHV11 terminal interface emulation resolves communication issue for pseudo-sessions using telnet now makes the emulated VAX quite workable. The powerful multitasking in VMS places no apparent load on the host system processor, which I take to be a sign that VMS has a much better underlying time sharing design than does either Windows or Linux. That does jibe with my VMS experiences, where a machine with only 32MB of RAM and a relatively slow processor by today's standards was able to provide subsecond response times to a couple dozen VT220 terminals, keep two tape drives and several disk drives busy, run multiple batch jobs (not all I/O limited either, as some were mostly mathematical or statistical) and still registered as much as 45% "idle" processor time. I've said it before, but it bears repeating: OpenVMS is a really amazing software design.