| Re: Gs bubble disease strikes again :-( |
Subject: Re: Gs bubble disease strikes again :-( by Anonymous on 6/10/2007 11:42:58 Have consulted one of my books, don't suppose this will tell you anything you don't know except the finger test is a handy tip for future. Here is info: Gas Bubble Disease (Tropical Fishlopaedia - Bailey & Burgess) Gas bubble disease results from gas (usually nitrogen) supersaturation of the aquarium water and is analogous to the ‘bends in human divers. Signs: Lethargy, usually with no other signs of disease; microscopical examination of the gills may reveal small bubbles on the gill filaments. If there are gas bubbles on the glass and other surfaces in the aquarium and the fish appear unwell, then suspect gas bubble disease. In acute cases the fish may have bubbles adhering to their external surfaces. Death may ensue, and sub-lethal exposure can result in brain damage. In the case of breeding and rearing aquaria, affected eggs and fry may become buoyant, and fry yolk-sacs visibly distended with gas. Cause: Gas (chiefly nitrogen) supersaturation of the water, usually occurring when cold gas-rich, water is heated quickly - as the temperature rises, its capacity for carrying gases decreases, leading to supersaturation and the formation of bubbles (the same phenomenon can be seen in saucepans of cold water put on to heat). Gas supersaturation commonly occurs where freshly-drawn (and hence likely to be gas-rich) cold water has been used to fill a newly set up aquarium and rapidly heated to operating temperature; or if cold, or rapidly warmed, water is used to refill after a large partial change. Fish exposed to such conditions breathe in the excess concentrations of gas which may subsequently come out of solution in the blood and cause gas embolism (the obstruction of blood vessels by gas bubbles). It is possible, but unlikely, that the use of high-turnover powerheads, with venturis, in too small an aquarium might also cause gas supersaturation. Sensible use of appropriate equipment will avoid any chance of this. Prevention: Freshly-drawn cold water should be warmed and aerated (to drive off excess gases) before being used for water changes. Fish should not be placed in a newly set up aquarium until it is biologically mature, buy which time excess gases will have dissipated naturally. Treatment: Move the fish to another, problem-free aquarium; otherwise drive off the excess gas by aerating vigorously or otherwise agitating the water. Comment: Specialised (and expensive) equipment is needed to measure nitrogen levels in water, but the ‘finger test’ can be used to test for gas supersaturation: if numerous bubbles form on a dry finger immersed in the aquarium for about a minute, there may be a supersaturation problem. This test can also be used for checking recently-drawn water before it is added to the aquarium |