Starting Over
 

I have a 46 gallon bow tank..It ran for YEARS and all of a sudden went bad. The tank had africians , I tried everything before I got to the stage of basically taking it down. At this point I have 50 pct of the water out no filtration and almost all the gravel out.

I am wondering if its necessary to take ALL the water and gravel out? I am STILL not sure what the issue in the tank was but I would like to get this going again, slowly. I would intend to rinse the gravel and dont know if i should take ALL of the GRAVEL and water out..

I need input on where to go from here? Thanks

Were it me, I would empty the tank and start anew. Most important aspect of keeping Africans is to ensure that the water is to their liking. A pH of 8.0 to 8.6 would suit most. If my tapwater was much below pH of 7.8, I would consider using gravel designed for African cichlid tanks. Water can be quite hard from the tap but over time,the biological processes that take place in a closed glass box of water, will tend to allow water to become softer (acidic). This would not suit the African cichlids.
Water changes each week can sometimes prevent or slow the rate at which the water becomes softer due to the decaying organics that build up over the months,years but In my view, a substrate such as coral sand or aragonite designed specifically for cichlid tanks would be the way forward.
Would take a sample of water used for water changes and have the pH tested if it is lower than 8.0 and africans is what i wanted to keep, i would consider the substrates mentioned.
If fishes died from disease,, then allowing the tank to run empty for a matter of three weeks would assure that most pathogens would die off for without a host fish to infect,, few pathogens can survive.
This would mean that the tank must once again ,be allowed to mature or (cycle). Hope some of this helps.