mums just come over and has a problem with her tank,she had two guppys die and a whole heap of snails,she does 90 % water changes every week so ive told her to change them to 30-50% instead and she adds water conditionar every time,her ph is fine and due to the water changes ammonia is fine too (tho at the end of the week its probobly spiked)

she says she does the big water changes because she gets alot of brown algae on everything but the tank is not in the sun?

any ideas on how to fix these probs?

Brown algae is not caused by sunlight. It's usually actually cleared up a bit by light and replaced by green algae.

Ive noticed that when ever i start a new tank, it goes through algae cycles. It starts with brown algae when all the media has cycled through. After that, the brown starts to disappear and is replaced by a furry coat of green algae. the green algae then remains and fish feed on it occasionally. And I have my lights on too long each day, the green algae slowly grows into long stringy hair algae. so i does occasionally with flourish to keep it at bay. HTH

What does she do to the filter when she does the 90% water changes? Is it possible the tank is re-cycling every week, hence the brown algae?