My first experience with ChessOK’s Aquarium back in 2010 was a disaster, but more recently I have purchased their latest Aquarium and aside from an initial problem downloading it, it has become my tool of choice for analyzing and playing engine-assisted chess on Lechenicher SchachServer. I might add that the initial problem was quickly addressed by their customer service.
There are several products available and the main difference is the engine supplied. Aquarium 2014 comes with Rybka 2.3 while Houdini 4 comes with the H4 engine; all products have a 6 million game database. Houdini 4 supports up to 6 cores and 4 GB of hash. Houdini 4 Aquarium offers advanced analysis functions, game commenting, searching, powerful chess trees, playing against the computer, databases, advanced publishing features and much more.
The biggest problem I ran into was that the Aquarium interface has so many bells and whistles that it was difficult for me to use it. I finally solved the problem by 1) reading a lot of the available material and 2) creating a practice database where I could mess around without boogering up anything. After a week or so of study I finally got to the place where I was fairly competent, but even now I haven’t yet mastered all its features.
Most important, especially for correspondence players playing on LSS or ICCF where engine use is allowed, or for anyone doing opening analysis, is the Interactive Deep Analysis feature.
The purpose of IDeA is to analyze a position deeply and return as much information about it as possible (often for us amateurs, more than we would ever want or need to know) to enable the user to get a better understanding of the nuances of any position.
The best part of IDeA, unlike Fritz’ Deep Positional Analysis, is that it keeps a permanent record of its analysis in a tree structure, which is unlimited in size. You can browse the analysis tree at will, both while the analysis is in progress and after it has finished. Also, you can direct the analysis into the positions that are of most interest to you by excluding or adding positions and variations. What this means is that analysis can be stopped at any time and the next time it is started, it resumes where it left off.
In addition to the Houdini 4 engine, you can also download other strong engines (recommended) like Critter or Stockfish to assist in analysis. Another really nice thing is that when analyzing a position you can configure Aquarium to analyze with several engines in a variety of different formats all at the same time (assuming you have more than one core, preferably at least 4cores).